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【327813】2023年湖北省鄂州市中考数学真题

时间:2025-01-20 20:20:29 作者: 字数:24255字
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2023年湖北省鄂州市中考数学真题

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得分




一、选择题

1.10的相反数是(       
A
.-10
B
10
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

2.下列运算正确的是(  )
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

3.中华鲟是地球上最古老的脊椎动物之一,距今约有140000000年的历史,是国家一级保护动物和长江珍稀特有鱼类保护的旗舰型物种,328日是中华鲟保护日,有关部门进行放流活动,实现鱼类物种的延续并对野生资源形成持续补充.将140000000用科学记数法表示应为(  )
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

4.下列立体图形中,主视图是圆的是(   
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

5.如图,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 于点E.若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的度数是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>        
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

6.已知不等式组 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的解集是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (  )
A
0
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
1
D
2023

7.象棋起源于中国,中国象棋文化历史悠久.如图所示是某次对弈的残图,如果建立平面直角坐标系,使棋子“帅”位于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的位置,则在同一坐标系下,经过棋子“帅”和“马”所在的点的一次函数解析式为(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

8.如图,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中点,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 长为半径作半圆,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则图中阴影部分的面积是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

9.如图,已知抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的对称轴是直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,且过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,顶点在第一象限,其部分图象如图所示,给出以下结论:① <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ;② <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ;③ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ;④若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> )是抛物线上的两点,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,其中正确的选项是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
A
.①②③
B
.①③④
C
.②③④
D
.①②④

10.如图,在平面直角坐标系中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为原点, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为平面内一动点, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上的一点,且满足 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .当线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取最大值时,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的坐标是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

评卷人

得分




二、填空题

11.计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> =_______

12.为了加强中学生“五项管理”,葛洪学校就“作业管理”、“睡眠管理”、“手机管理”、“读物管理”、“体质管理”五个方面对各班进行考核打分(各项满分均为100),九(1)班的五项得分依次为9590859092,则这组数据的众数是___________

13.实数mn分别满足 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值是_______

14.如图,在平面直角坐标系中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 位似,原点O是位似中心,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 点的坐标是___________
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    

15.如图,在平面直角坐标系中,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 与双曲线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> )相交于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 两点,过点B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴,交y轴于点P,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的面积是___________
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    

16.2002年的国际数学家大会在中国北京举行,这是21世纪全世界数学家的第一次大聚会.这次大会的会徽选定了我国古代数学家赵爽用来证明勾股定理的弦图,世人称之为“赵爽弦图”.如图,用四个全等的直角三角形( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> )拼成“赵爽弦图”,得到正方形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 与正方形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 分别相交于点POQ,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值是___________
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    

评卷人

得分




三、解答题

17.先化简,再求值: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

18.如图,点E是矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上的一点,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
(1)尺规作图(请用 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 铅笔):作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的平分线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的延长线于点F,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .(保留作图痕迹,不写作法);
(2)
试判断四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的形状,并说明理由.

19.为庆祝建党100周年,让同学们进一步了解中国科技的快速发展,东营市某中学九(1)班团支部组织了一次手抄报比赛.该班每位同学从A.“北斗卫星”;B.“5G时代”;C.“东风快递”;D.“智轨快运”四个主题中任选一个自己喜欢的主题.统计同学们所选主题的频数,绘制成以下不完整的统计图,请根据统计图中的信息解答下列问题:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
1)九(1)班共有________名学生;
2)补全折线统计图;
3D所对应扇形圆心角的大小为________
4)小明和小丽从ABCD四个主题中任选一个主题,请用列表或画树状图的方法求出他们选择相同主题的概率.

20.鄂州市莲花山是国家 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 级风景区,元明塔造型独特,是莲花山风景区的核心景点,深受全国各地旅游爱好者的青睐.今年端午节,景区将举行大型包粽子等节日庆祝活动.如图2,景区工作人员小明准备从元明塔的点G处挂一条大型竖直条幅到点E处,挂好后,小明进行实地测量,从元明塔底部F点沿水平方向步行30米到达自动扶梯底端A点,在A点用仪器测得条幅下端E的仰角为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ;接着他沿自动扶梯 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 到达扶梯顶端D点,测得点A和点D的水平距离为15米,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ;然后他从D点又沿水平方向行走了45米到达C点,在C点测得条幅上端G的仰角为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .(图上各点均在同一个平面内,且GCB共线,FAB共线,GEF共线, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ).
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>     <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
(1)求自动扶梯 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长度;
(2)
求大型条幅 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长度.(结果保留根号)

21.1号探测气球从海拔 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 处出发,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的速度竖直上升.与此同时,2号探测气球从海拔20m处出发,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的速度竖直上升.两个气球都上升了 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 1号、2号气球所在位置的海拔 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (单位:m)与上升时间x(单位: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> )的函数关系如图所示.请根据图象回答下列问题:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ___________ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ___________
(2)
请分别求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x的函数关系式;
(3)
当上升多长时间时,两个气球的海拔竖直高度差为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

22.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的直径,E <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上一点,点C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中点,过点C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的延长线于点D,延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的延长线于点F
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
(1)求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的切线;
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的半径长.

23.某数学兴趣小组运用《几何画板》软件探究 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 型抛物线图象.发现:如图1所示,该类型图象上任意一点P到定点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的距离 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,始终等于它到定直线l <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的距离 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (该结论不需要证明).他们称:定点F为图象的焦点,定直线l为图象的准线, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 叫做抛物线的准线方程.准线ly轴的交点为H.其中原点O <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中点, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .例如,抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,其焦点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,准线方程为l <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
(基础训练)
(1)
请分别直接写出抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的焦点坐标和准线l的方程:______________________
(
技能训练)
(2)
如图2,已知抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上一点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 到焦点F的距离是它到x轴距离的3倍,求点P的坐标;
(
能力提升)
(3)
如图3,已知抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的焦点为F,准线方程为l.直线m <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> y轴于点C,抛物线上动点Px轴的距离为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,到直线m的距离为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,请直接写出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的最小值;
(
拓展延伸)
该兴趣小组继续探究还发现:若将抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 平移至 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 内有一定点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,直线l过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 且与x轴平行.当动点P在该抛物线上运动时,点P到直线l的距离 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 始终等于点P到点F的距离(该结论不需要证明).例如:抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上的动点P到点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的距离等于点P到直线l <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的距离.
请阅读上面的材料,探究下题:
(4)
如图4,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是第二象限内一定点,点P是抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上一动点,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取最小值时,请求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的面积.

24.如图1,在平面直角坐标系中,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴,交y轴的正半轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,点By轴右侧直线l上的一动点,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    

(1)请直接写出点A的坐标;
(2)
如图2,若动点B满足 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,点C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中点, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 点为线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上一动点,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .在平面内,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 沿 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 翻折,点B的对应点为点P <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 相交于点Q,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,求线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长;
(3)
如图3,若动点B满足 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中位线,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 绕点B在平面内逆时针旋转,当点OEF三点共线时,求直线EBx轴交点的坐标;
(4)
如图4 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的一条中线.设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的周长分别为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .试探究:在B点的运动过程中,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,请直接写出点B的坐标.

参考答案

1.A

【解析】
根据相反数的定义直接求解.
解:10的相反数是-10
故选:A

2.B

【解析】
根据同底数幂的加法,同底数幂的乘除法,幂的乘方这些公式进行运算即可.
A
选项, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 不是同类项,不能合并,故不符合题意;
B
选项, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,正确,故符合题意;
C
选项, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,不正确,故不符合题意;
D
选项, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,不正确,故不符合题意.
故选:B

3.B

【解析】
科学记数法的表示形式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的形式,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> n为整数.确定n的值时,要看把原数变成a时,小数点移动了多少位,n的绝对值与小数点移动的位数相同.当原数绝对值 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,n是正数;当原数的绝对值 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,n是负数.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选B

4.D

【解析】
分别得出棱柱,圆柱,圆锥,球体的主视图,得出结论.
解:棱柱的主视图是矩形(中间只有一条线段),不符合题意;
圆柱的主视图是矩形,不符合题意;
圆锥的主视图是等腰三角形,不符合题意;
球体的主视图是圆,符合题意;
故选:D

5.B

【解析】
延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,与 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据平行线的性质,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的度数,再直角三角形的两锐角互余即可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解:延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,与 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选:B

6.B

【解析】
按照解一元一次不等式组的步骤进行计算,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,再结合已知可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,然后进行计算可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值,最后代入式子中进行计算即可解答.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解不等式①得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解不等式②得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
原不等式组的解集为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
不等式组的解集是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选:B

7.A

【解析】
利用待定系数法求解一次函数即可得解.
解:如图,建立平面直角坐标系,可得“马”所在的点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
设经过棋子“帅”和“马”所在的点的一次函数解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
经过棋子“帅”和“马”所在的点的一次函数解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选A

8.C

【解析】
连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,首先根据勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长度,然后利用解直角三角形求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长度,进而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是等边三角形, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,然后根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 角直角三角形的性质求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长度,最后根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 进行计算即可.
解:如图所示,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中点,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 长为半径作半圆,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是半圆的直径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是等边三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选:C

9.D

【解析】
根据二次函数的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,可判断结论①;由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 处的函数值可判断结论②;由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 处函数值可判断结论③;根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 得到点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 到对称轴的距离小于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 到对称轴的距离可判断结论④.
解:二次函数开口向下,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
二次函数对称轴为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,故①正确;
过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
由对称性可得二次函数与 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴的另一交点为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
由函数图象可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,故②正确;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 代入得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,故③错误;
对称轴是直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 到对称轴的距离小于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 到对称轴的距离
二次函数开口向下
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,故④正确.
综上所述,正确的选项是①②④.
故选: D

10.D

【解析】
由题意可得点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 在以点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为半径的 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴的负半轴上取点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,分别过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,垂足为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,先证 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,从而当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取得最大值时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取得最大值,结合图形可知当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 三点共线,且点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 在线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取得最大值,然后分别证 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,利用相似三角形的性质即可求解.
解:∵点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为平面内一动点, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 在以点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为半径的 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴的负半轴上取点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,分别过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,垂足为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取得最大值时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取得最大值,结合图形可知当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 三点共线,且点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 在线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取得最大值,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
同理可得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
当线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取最大值时,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的坐标是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故选D

11.4

【解析】
根据算术平方根的概念求解即可.算术平方根的定义:一个非负数的正的平方根,即为这个数的算术平方根,由此即可求出结果.
解:原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> =4
故答案为4

12.90

【解析】
众数是在一组数据中,出现次数最多的数据.
众数是在一组数据中,出现次数最多的数据,这组数据中90出现2次,出现的次数最多,故这组数据的众数为90
故答案为:90

13. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
直接利用根与系数的关系进行求解即可.
解:由题可知,mn <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的两个根,
所以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
所以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

14. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
直接利用位似图形的性质得出相似比进而得出对应线段的长.
解∶设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 位似,原点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是位似中心,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> .若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
位似比为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

15. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 代入到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 可求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值,再把 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 代入双曲线函数的表达式中,可求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值,进而利用三角形的面积公式进行求解即可.
直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 与双曲线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> )相交于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 两点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
双曲线的表达式为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

16. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,利用相似三角形的性质求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,利用勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,进而可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长,再证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,然后根据正方形的性质求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即可得出答案.
解:设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
整理得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (舍去),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是正方形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

17. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
根据题意,先进行同分母分式加减运算,再将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 代入即可得解.
解:原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

18.(1)见解析
(2)
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是菱形,理由见解析

【解析】
1)根据题意结合尺规作角平分线的方法作图即可;
2)根据矩形的性质和平行线的性质得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,结合角平分线的定义可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,然后根据平行四边形和菱形的判定定理得出结论.
1)解:如图所示:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
2)四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是菱形;
理由:∵矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是平行四边形,
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
平行四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是菱形.

19.150;(2)见解析;(3108°;(4 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)用B组频数除以所占百分比即可求解;
2)用50减去ABC组频数,求出D组频数,即可补全折线统计图;
3)用360°乘以D组所占百分比即可求解;
4)列表得出所有等可能结果,根据概率公式即可求解.
120÷40%=50(人),
故答案为:50
250-10-20-5=15(人),
补全折线统计图如图:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
4)列表如下:

小明


小丽

A

B

C

D

A

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

B

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

C

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

D

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

由列表可知,一共有16种等可能的结果,他们选择相同主题的结果有4种,
所以P(相同主题) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

20.(1)25
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)过D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> M,由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长,利用勾股定理即可求解;
2)过点D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> N,则四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是矩形,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,由已知计算得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长度,解直角三角形得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长度,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 中求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长度,利用线段的和差,即可解决问题.
1)解:过D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> M,如图:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ()
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ()
由勾股定理得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ()
2)如图,过点D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> N
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> () <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ()
由题意, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ()
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> () <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (米),
由题意, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ()
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ()
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

21.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 30
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)根据1号探测气球的出发海拔和速度即可计算b的值,根据b的值、2号探测气球的出发海拔和运动时间可计算2号探测气球的速度可计算a的值;
2)由(1)可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 函数图象的交点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,分别代入计算即可;
3)由题意可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,分别计算即可.
1)解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 30
2)由(1)可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 函数图象的交点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 分别代入可得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
3)由题意可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
当上升 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 时,两个气球的海拔竖直高度差为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

22.(1)证明见解析
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据弦、弧、圆周角的关系可证 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据圆的性质得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据切线的判定定理证明;
2)连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据勾股定理得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的长,根据等弧对等弦得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据圆内接四边形对角互补得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,利用相似三角形的性质即可求解.
1)证明:连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>      
C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 为半径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 切线;
2)解:连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的直径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的半径长为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

23.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(4)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)根据题中所给抛物线的焦点坐标和准线方程的定义求解即可;
2)利用两点间距离公式结合已知条件列式整理得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,然后根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,进而可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,问题得解;
3)过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 准线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,结合题意和(1)中结论可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据两点之间线段最短可得当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 三点共线时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值最小;待定系数法求直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的解析式,求得点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 和直线m的交点,求得点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即可求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值,即可求得;
4)根据题意求得抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的焦点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,准线l的方程为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 准线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,结合题意和(1)中结论可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,根据两点之间线段最短可得当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 三点共线时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值最小;求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即可求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的面积.
1)解:∵抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的焦点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,准线l的方程为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
2)解:由(1)知抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的焦点F的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 到焦点F的距离是它到x轴距离的3倍,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,整理得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (舍去),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
P的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
3)解:过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 准线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,结合题意和(1)中结论可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,如图:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
若使得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取最小值,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值最小,故当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 三点共线时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即此刻 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值最小;
直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 与直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 垂直,故设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 代入解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 和抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的交点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (舍去),
故点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 和直线m的交点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
故点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的最小值为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
4)解:∵抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的焦点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,准线l的方程为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 准线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,结合题意和(1)中结论可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,如图:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
若使得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 取最小值,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值最小,故当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 三点共线时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即此刻 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的值最小;如图:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 准线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的横坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的面积为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

24.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
(4)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>

【解析】
1)根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,点A位于y轴的正半轴即可得出答案;
2)根据折叠性质和特殊角解三角形,先求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,再过点D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 解三角形即可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,从而求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
3)将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 绕点B在平面内逆时针旋转,当点OEF三点共线时,有两种情况,当将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 绕点B在平面内逆时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,可得点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> F恰好落在x轴, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,从而可得直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x轴交点的坐标;当将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 绕点B在平面内逆时针旋转到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 上方时,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,从而得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,继而可求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,再由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 即可求出交点坐标.
4)由已知可证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,进而可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,由此可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> H点,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,然后由双勾股求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,进而求出点B坐标.
1)解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,点A位于y轴的正半轴,
A坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
2)∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
由折叠可知: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
如解(2)图,过点D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
3)解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的中位线,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
I.如图,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 绕点B在平面内逆时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,到如解(3-1图所示位置时,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> F恰好落在x轴, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
此时直线EBx轴交点的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
II.如图,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 绕点B在平面内逆时针旋转到点OEF三点共线时,,如解(3-2图所示位置时,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x轴于点K
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴,
直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
此时直线EBx轴交点的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
综上所述:将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 绕点B在平面内逆时针旋转,当点OEF三点共线时,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> x轴交点的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
4)直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 轴, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 于点D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的一条中线.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> ,即: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> 的周长分别为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> H点,如解(4)图,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
解得:  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a> (不合题意,舍去), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>
所以点B坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/557/" title="湖北" class="c1" target="_blank">湖北</a> <a href="/tags/975/" title="湖北省" class="c1" target="_blank">湖北省</a> <a href="/tags/1103/" title="鄂州" class="c1" target="_blank">鄂州</a>