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【327854】2023年辽宁省营口市中考数学真题

时间:2025-01-20 20:29:19 作者: 字数:21451字
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2023年辽宁省营口市中考数学真题

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得分





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1.答题前填写好自己的姓名、班级、考号等信息

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评卷人

得分




一、选择题

1. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的绝对值是( )
A
3
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

2.如图是由五个相同的正方体搭成的几何体,这个几何体的主视图是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    

3.有下列四个算式① <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;② <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;③ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;④ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> .其中,正确的有(       ).
A
0
B
1
C
2
D
3

4.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的平分线, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的度数是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
A50°
B
40°
C
35°
D
45°

5.下列计算结果正确的是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

6.下列事件是必然事件的是(       
A
.四边形内角和是360°
B
.校园排球比赛,九年一班获得冠军
C
.掷一枚硬币时,正面朝上
D
.打开电视,正在播放神舟十六号载人飞船发射实况

7.不等式组 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解集在数轴上表示正确的是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    

8.2台大收割机和5台小收割机同时工作2小时共收割小麦3.6公顷,3台大收割机和2台小收割机同时工作5小时共收割小麦8公顷.1台大收割机和1台小收割机每小时各收割小麦多少公顷?设1台大收割机和1台小收割机每小时各收割小麦x公顷和y公顷,根据题意,可列方程组为(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

9.如图所示, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的直径,弦 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于点E,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的度数是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

10.如图.抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> x轴交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 和点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,与y轴交于点C.下列说法:① <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;②抛物线的对称轴为直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;③当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;④当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,yx的增大而增大;⑤ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> m为任意实数)其中正确的个数是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
A1
B
2
C
3
D
4

评卷人

得分




二、填空题

11.若二次根式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 有意义,则x的取值范围是______

12.在平面直角坐标系中,将点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 向左平移5个单位长度,得到点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的坐标是______

13.某班35名同学一周课外阅读时间统计如表所示

时间/小时

7

8

9

10

人数

4

12

13

6

则该班35名同学一周课外阅读时间的众数是______小时.

14.若关于x的方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的一个根是3,则此方程的另一个根是______

15.如图,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中,以A为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 长为半径作弧,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> CD两点,分别以点C和点D为圆心,大于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 长为半径作弧,两弧交于点P,作直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于点E,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ______
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    

16.如图,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 绕着点C按顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,连接BD <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于在E,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ______
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</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/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

18.某校在评选“劳动小能手”活动中,随机调查了部分学生的周末家务劳动时间,根据调查结果,将劳动时长划分为ABCD四个组别,并绘制成如下不完整统计图表
学生周末家务劳动时长分组表

组别

A

B

C

D

t(小时)

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
请根据图表中的信息解答下列问题:
(1)
这次抽样调查共抽取______名学生,条形统计图中的 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ______D组所在扇形的圆心角的度数是______
(2)
已知该校有900名学生,根据调查结果,请你估计该校周末家务劳动时长不低于1小时的学生共有多少人?
(3)
班级准备从周末家务劳动时间较长的三男一女四名学生中,随机抽取两名学生参加“我劳动,我快乐”的主题演讲活动,请用列表法或画树状图法求出恰好选中两名男生的概率.

19.如图.点ABCD在同一条直线上,点EF分别在直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的两侧,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
(1)求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的长.

20.如图,点A在反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的图象上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴于点B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
(1)求反比例函数的解析式;
(2)
C在这个反比例函数图象上,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 并延长交x轴于点D,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,求点C的坐标.

21.为了丰富学生的文化生活,学校利用假期组织学生到素质教育基地A和科技智能馆B参观学习,学生从学校出发,走到C处时,发现A位于C的北偏西 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 方向上,B位于C的北偏西 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 方向上,老师将学生分成甲乙两组,甲组前往A地,乙组前往B地,已知BA的南偏西 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 方向上,且相距1000米,请求出甲组同学比乙组同学大约多走多远的路程(参考数据: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    

22.某大型超市购进一款热销的消毒洗衣液,由于原材料价格上涨,今年每瓶洗衣液的进价比去年每瓶洗衣液的进价上涨4元,今年用1440元购进这款洗衣液的数量与去年用1200元购进这款洗衣液的数量相同.当每瓶洗衣液的现售价为36元时,每周可卖出600瓶,为了能薄利多销.该超市决定降价销售,经市场调查发现,这种洗衣液的售价每降价1元,每周的销量可增加100瓶,规定这种消毒洗衣液每瓶的售价不低于进价.
(1)
求今年这款消毒洗衣液每瓶进价是多少元;
(2)
当这款消毒洗衣液每瓶的售价定为多少元时,这款洗衣液每周的销售利润最大?最大利润是多少元?

23.如图,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 为直径作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 交于点D,过点D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 延长线于点F,垂足为点E
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
(1)
求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的切线;
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的长.

24. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,点E <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 上,点G <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 上,点F <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的延长线上,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>     <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>     <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
(1)如图1,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,请用等式表示线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 与线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的数量关系______
(2)
如图2,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,写出线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 之间的数量关系,并说明理由;
(3)
在(2)的条件下,当点G <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的中点时,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的值.

25.如图,抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 和点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,与 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,抛物线的对称轴交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 作直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,交直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
(1)求抛物线的解析式;
(2)
如图,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 为第三象限内抛物线上的点,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时.求点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的坐标;
(3)
在(2)的条件下,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,在直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 上是否存在点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,使得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ?若存在,请直接写出点F的坐标;若不存在,请说明理由.

参考答案

1.C

【解析】
根据数轴上某个数与原点的距离叫做这个数的绝对值,依据定义即可求解.
在数轴上,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 到原点的距离是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
所以, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的绝对值是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故选:C

2.B

【解析】
根据主视图是从正面看到的图形进行求解即可.
解:从正面看,看到的图形分为上下两层,下面一层有3个小正方形并排放在一起,上面一层最中间有1个小正方形,
即看到的图形为
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
故选B

3.C

【解析】
由有理数的加减运算法则、乘方的运算法则、除法运算法则,分别进行判断,即可得到答案.
解:① <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;故①错误;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;故②错误;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;故③正确;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ;故④正确;
故选:C

4.B

【解析】
根据邻补角求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,利用角平分线求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,再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/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的度数.
解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的平分线,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故选:B

5.B

【解析】
根据同底数幂的乘法和除法,积的乘方以及合并同类项的运算法则进行计算,逐个判断.
解:A.  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,原计算错误,故此选项不符合题意;
B.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,计算正确,故此选项符合题意;       
C.  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,原计算错误,故此选项不符合题意;       
D.  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,原计算错误,故此选项不符合题意.
故选:B

6.A

【解析】
根据事件发生的可能性大小判断相应事件的类型即可.
解:A、四边形内角和是360°是必然事件,故此选项符合题意;
B
、校园排球比赛,九年一班获得冠军是随机事件,故此选项不符合题意;
C
、掷一枚硬币时,正面朝上是随机事件,故此选项不符合题意;
D
、打开电视,正在播放神舟十六号载人飞船发射实况是随机事件,故此选项不符合题意;
故选:A

7.B

【解析】
解出不等式组的解集,在数轴上表示,含端点值用实心圆圈,不含端点值用空心圆圈,即可求解.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解不等式①得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解不等式②得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
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/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
数轴表示如下所示:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
故选B

8.C

【解析】
根据” 2台大收割机和5台小收割机同时工作2小时共收割小麦3.6公顷,3台大收割机和2台小收割机同时工作5小时共收割小麦8公顷”列方程组即可.
解:设1台大收割机和1台小收割机每小时各收割小麦x公顷和y公顷,
根据2台大收割机和5台小收割机同时工作2小时共收割小麦3.6公顷,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
根据3台大收割机和2台小收割机同时工作5小时共收割小麦8公顷,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
可列 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故选:C

9.D

【解析】
如图所示,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,先由同弧所对的圆周角相等得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,再由直径所对的圆周角是直角得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解:如图所示,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的直径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故选D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    

10.C

【解析】
根据抛物线开口向下,与y轴交于正半轴,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 和点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 可得抛物线的对称轴为直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即可判断②;推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即可判断①;根据函数图象即可判断③④;根据当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,抛物线有最大值 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即可得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即可判断⑤.
解:∵抛物线开口向下,与y轴交于正半轴,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
抛物线与x轴交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 和点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
抛物线对称轴为直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,故②正确;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,故①错误;
由函数图象可知,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,抛物线的函数图象在x轴上方,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,故③正确;
抛物线对称轴为直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 且开口向下,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,yx的增大而减小,即当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,yx的增大而减小,故④错误;
抛物线对称轴为直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 且开口向下,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,抛物线有最大值 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,故⑤正确;
综上所述,正确的有②③⑤,
故选C

11. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
根据二次根式有意义的条件得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,解不等式即可得到答案.
解:∵二次根式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 有意义,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

12. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
向左平移5个单位长度,即点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的横坐标减5,纵坐标不变,从而即可得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的坐标.
解:点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 向左平移5个单位长度后,
坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

13.9

【解析】
一组数据中出现次数最多的数据即为众数,根据定义解答.
解:35个数据中7出现4次,8出现12次,9出现13次,10出现6次,
∴9
出现的次数最多,
众数为9小时,
故答案为:9

14. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
根据根与系数的关系 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 即可求出方程的另一个根.
设另一个根为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
根据题意: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
即另一个根为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

15.4

【解析】
利用圆的性质得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 垂直平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,运用勾股定理便可解决问题.
解:根据题意可知,以点C和点D为圆心,大于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 长为半径作弧,两弧交于点P
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 垂直平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> , <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
又∵在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中,以A为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 长为半径作弧,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> CD两点,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故答案为:4

16. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 是等边三角形,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,取 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的中点H,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,再利用勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,进一步即可得到答案.
解:连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 绕着点C按顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 是等边三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的中点H,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

17. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
先根据分式的混合计算法则化简,然后根据特殊角三角函数值和二次根式的性质求出m的值,最后代值计算即可.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

18.(1)509 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
(2)
估计该校周末家务劳动时长不低于1小时的学生共有666人;
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
1)根据数据计算即可;
2)根据(1)求出的D组所占的比例计算结果;
3)列出所有可能情况求概率.
1)解:这次抽样调查共抽取的人数有: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (人),
B组的人数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (人),
D组所占的比例为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
D组所在扇形的圆心角的度数是: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
2)解:根据题意得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (人)
答:估计该校周末家务劳动时长不低于1小时的学生共有666人;
3)解:列表如下:


1

2

3

1


(男2,男1

(男3,男1

(女,男1

2

(男1,男2


(男3,男2

(女,男2

3

(男1,男3

(男2,男3


(女,男3

(男1,女)

(男2,女)

(男3,女)



共有12中等可能结果,其中恰好选中两名男生的结果数为6
恰好选中两名男生的概率 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> .

19.(1)证明见解析
(2)4

【解析】
1)直接利用 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 即可;
2)根据全等三角形的性质得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
1)证明:在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
2)解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

20.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
1)利用正切值,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,进而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即可求出反比例函数的解析式;
2)过点A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴于点E,易证四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 是矩形,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,再证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 是等腰直角三角形,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,进而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,然后利用待定系数法求出直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,联立反比例函数和一次函数,即可求出点C的坐标.
1)解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> A在反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的图象上,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 反比例函数的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
2)解:如图,过点A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴于点E
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 是等腰直角三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> AC是反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 和一次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的交点,
联立 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    

21.甲组同学比乙组同学大约多走 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 米的路程

【解析】
B点作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于点D,根据题意有: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,进而可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,结合直角三角形的知识可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),即有 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),问题随之得解.
如图,过B点作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于点D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
根据题意有: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (米),
答:甲组同学比乙组同学大约多走 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 米的路程.

22.(1)今年这款消毒洗衣液每瓶进价是24元;
(2)
当这款消毒洗衣液每瓶的售价定为33元时,这款洗衣液每周的销售利润最大,最大利润是8100元.

【解析】
1)设今年这款消毒洗衣液每瓶进价是x元,则去年这款消毒洗衣液每瓶进价是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 元,根据题意列出分式方程,解方程即可;
2)设这款消毒洗衣液每瓶的售价定为m元时,这款洗衣液每周的销售利润w最大,根据题意得出: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,根据二次函数的性质可得出答案.
1)解:设今年这款消毒洗衣液每瓶进价是x元,则去年这款消毒洗衣液每瓶进价是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 元,
根据题意可得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
经检验: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 是方程的解,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 元,
答:今年这款消毒洗衣液每瓶进价是24.
2)解:设这款消毒洗衣液每瓶的售价定为m元时,这款洗衣液每周的销售利润w最大,
根据题意得出: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
整理得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
根据二次函数的性质得出:当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,利润最大,
最大利润为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
答:当这款消毒洗衣液每瓶的售价定为33元时,这款洗衣液每周的销售利润最大,最大利润是8100元.

23.(1)见详解
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
1)连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,根据圆周角定理证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,再根据“三线合一”证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即有 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,进而可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,问题得证;
2)先证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即有 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中结合勾股定理,可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即同理在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,进而有 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即有 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,问题即可得解.
1)连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的直径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
半径 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的切线;
2)∵在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
在(1)中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (负值舍去),
即同理在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (经检验,符合题意),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

24.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
1)当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 上截取 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
2)当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,过点G <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于点M,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,由此得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,进而推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
3)由(2)得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,由点G <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的中点,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,过点E <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> N,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 角的性质及勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即可得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,根据公式计算即可.
1)解:当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 上截取 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,理由如下:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
过点G <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于点M
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
3)∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
G <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
过点E <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> N
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

25.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>

【解析】
1)根据抛物线过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,对称轴为直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,待定系数法求解析式即可求解;
2)根据题意求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,进而求得直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,根据已知条件得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,将点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,即可求解.
3)根据题意可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 为对角线作正方形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,进而求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的坐标,待定系数法求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式,联立 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 解析式,即可求解.
1)解:∵抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,抛物线的对称轴交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则对称轴为直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
抛物线解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
2)解:由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
如图所示,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 轴,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
将点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> (舍去)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
3)∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 是等腰直角三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,由(2)可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
由(2)可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
如图所示,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 为对角线作正方形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> 解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a> , <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>
综上所述, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/990/" title="辽宁省" class="c1" target="_blank">辽宁省</a> <a href="/tags/1059/" title="营口" class="c1" target="_blank">营口</a> <a href="/tags/1122/" title="辽宁" class="c1" target="_blank">辽宁</a>