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【327808】2023年黑龙江省大庆市中考数学真题

时间:2025-01-20 20:19:30 作者: 字数:22704字
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2023年黑龙江省大庆市中考数学真题

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一、选择题

1. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的相反数是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

2.搭载神舟十六号载人飞船的长征二号 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 遥十六运载火箭于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 日成功发射升空,景海鹏、朱杨柱、桂海潮 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 名航天员开启“太空出差”之旅,展现了中国航天科技的新高度.下列图标中,其文字上方的图案是中心对称图形的是(        
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>         
D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    

3.大庆油田发现预测地质储量12.68亿吨的页岩油,这标志着我国页岩油勘探开发取得重大战略突破.数字1268000000用科学记数法表示为(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

4.一个长方体被截去一部分后,得到的几何体如图水平放置,其俯视图是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    

5.已知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则在如图所示的平面直角坐标系中,小手盖住的点的坐标可能是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

6.某中学积极推进学生综合素质评价改革,该中学学生小明本学期德、智、体、美、劳五项的评价得分如图所示,则小明同学五项评价得分的众数、中位数、平均数分别为(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
A99 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
99 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
88 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
98 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

7.下列说法正确的是(       
A
.一个函数是一次函数就一定是正比例函数
B
.有一组对角相等的四边形一定是平行四边形
C
.两条直角边对应相等的两个直角三角形一定全等
D
.一组数据的方差一定大于标准差

8.端午节是我国传统节日,端午节前夕,某商家出售粽子的标价比成本高25%,当粽子降价出售时,为了不亏本,降价幅度最多为(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

9.将两个完全相同的菱形按如图方式放置,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>        
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

10.如图1,在平行四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,已知点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 上,以1m/s的速度从点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 向点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 运动,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 上,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的速度从点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 向点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 运动.若点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 同时出发,当点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 到达点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 恰好到达点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 处,此时两点都停止运动.图2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的面积 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 与点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的运动时间 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 之间的函数关系图象(点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为图象的最高点),则平行四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的面积为(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

评卷人

得分




二、填空题

11.为了调查某品牌护眼灯的使用寿命,比较适合的调查方式是________(填“普查”或“抽样调查”).

12.一个圆锥的底面半径为5,高为12,则它的体积为________

13.在综合与实践课上,老师组织同学们以“矩形的折叠”为主题开展数学活动.有一张矩形纸片 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 如图所示,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 上,现将矩形折叠,折痕为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 对应的点记为点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,若点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 恰好落在边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 上,则图中与 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 一定相似的三角形是________
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    

14.已知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则x的值为_____

15.新高考“3+1+2”选科模式是指,除语文、数学、外语3门科目以外,学生应在历史和物理2门首选科目中选择1科,在思想政治、地理、化学、生物学4门再选科目中选择2科.某同学从4门再选科目中随机选择2科,恰好选择地理和化学的概率为________

16.若关于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的不等式组 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 有三个整数解,则实数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的取值范围为________

17.1261年,我国宋朝数学家杨辉在其著作《详解九章算法》中提到了如图所示的数表,人们将这个数表称为“杨辉三角”.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>        
观察“杨辉三角”与右侧的等式图,根据图中各式的规律, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 展开的多项式中各项系数之和为____

18.如图,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 绕点A顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 绕点A逆时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,使 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,我们称 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的“旋补三角形”, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的中线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 叫做 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的“旋补中线”,点A叫做“旋补中心”.下列结论正确的有________
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 面积相同;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

评卷人

得分




三、解答题

19.计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

20.先化简,再求值: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

21.为营造良好体育运动氛围,某学校用 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 元购买了一批足球,又用 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 元加购了第二批足球,且所购数量是第一批购买数量的 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 倍,但单价降了 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 元,请问该学校两批共购买了多少个足球?

22.某风景区观景缆车路线如图所示,缆车从点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 出发,途经点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 后到达山顶 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 段的运行路线与水平方向的夹角为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 段的运行路线与水平方向的夹角为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,求垂直高度 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> .(结果精确到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米,参考数据: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    

23.为了解我校学生本学期参加志愿服务的情况,随机调查了我校的部分学生,根据调查结果,绘制出如图统计图,若我校共有1000名学生,请根据相关信息,解答下列问题:
    <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
(1)本次接受调查的学生人数为________,扇形统计图中的 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ________
(2)
求所调查的学生本学期参加志愿服务次数的平均数;
(3)
学校为本学期参加志愿服务不少于7次的学生颁发“志愿者勋章”,请估计我校获“志愿者勋章”的学生人数.

24.如图,在平行四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的中点,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(1)
求证:四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是矩形;
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,求四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的面积.

25.一次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 与反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的图象交于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 两点,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
(1)求一次函数和反比例函数的表达式;
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的面积;
(3)
过动点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 轴的垂线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 与一次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 和反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的图象分别交于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 两点,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的上方时,请直接写出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的取值范围.

26.某建筑物的窗户如图所示,上半部分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是等腰三角形, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 分别是边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的中点;下半部分四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是矩形, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,制造窗户框的材料总长为16米(图中所有黑线的长度和),设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(1)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 之间的函数关系式,并求出自变量 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的取值范围;
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为多少时,窗户透过的光线最多(窗户的面积最大),并计算窗户的最大面积.

27.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的直径,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是圆上的一点, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
(1)求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的切线;
(2)
求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值.

28.如图,二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的图象与 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 轴交于A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 两点,且自变量 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的部分取值与对应函数值 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 如下表:

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
                                                            备用图
(1)
求二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的表达式;
(2)
若将线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 向下平移,得到的线段与二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的图象交于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 两点( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 左边), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的图象上的一点,当点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的横坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的横坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值;
(3)
若将线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 先向上平移3个单位长度,再向右平移1个单位长度,得到的线段与二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的图象只有一个交点,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为常数,请直接写出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的取值范围.

参考答案

1.B

【解析】
根据只有符号不同的两个数互为相反数进行解答即可得.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的相反数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:B

2.C

【解析】
根据中心对称图形的定义判断即可.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 、不是中心对称图形,此选项不符合题意,排除;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 、不是中心对称图形,此选项不符合题意,排除;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 、是中心对称图形,此选项符合题意;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 、不是中心对称图形,此选项不符合题意,排除;
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

3.A

【解析】
科学记数法的表现形式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的形式,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为整数,确定 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值时,要看把原数变成 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时,小数点移动了多少位, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的绝对值与小数点移动的位数相同,当原数绝对值大于等于10时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是非负数,当原数绝对值小于1时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是负数.
解:数字1268000000用科学记数法表示为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:A

4.A

【解析】
根据几何体三视图的画法解答.
解:该几何体的俯视图是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
故选:A

5.D

【解析】
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,再逐项分析即可得到答案.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 同号,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
A.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在第一象限,因为小手盖住的点在第四象限,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/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在第二象限,因为小手盖住的点在第四象限,故此选项不符合题意;
C.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在第三象限,因为小手盖住的点在第四象限,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/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在第四象限,因为小手盖住的点在第四象限,故此选项符合题意;
故选:D

6.B

【解析】
利用众数、中位数及平均数的定义写出答案即可.
解:该同学五项评价得分从小到大排列分别为789910
出现次数最多的数是9,所以众数为9
位于中间位置的数是9,所以中位数是9
平均数为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:B

7.C

【解析】
根据正比例函数的定义、平行四边形的判定、直角三角形全等的判定、标准差的概念对各选项进行判断,选出正确答案即可.
解:A、一个函数是一次函数不一定是正比例函数,故本选项不符合题意;
B
、有两组对角相等的四边形一定是平行四边形,故本选项不符合题意;
C
、两条直角边对应相等的两个直角三角形一定全等,故本选项符合题意;
D
、一组数据的方差不一定大于这组数据的标准差,故本选项不符合题意;
故选:C

8.A

【解析】
设粽子的成本为a元,设降价幅度为x,根据降价出售后不亏本即售价不低于进价列出不等式,解不等式即可得到答案.
解:设粽子的成本为aa是常数且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> )元,设降价幅度为x
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
即为了不亏本,降价幅度最多为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:A

9.D

【解析】
由题意可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,由菱形的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,由平行线的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,进行计算即可得到答案.
解:根据题意可得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为菱形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:D

10.C

【解析】
根据题意可得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的延长线于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的延长线于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,从而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的最大值为3,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值,从而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,最后由平行四边形的面积公式进行计算即可得到答案.
解:根据题意可得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的延长线于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的延长线于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
由图象可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的最大值为3
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (舍去),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 平行四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的面积为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:C

11.抽样调查

【解析】
根据全面调查得到的结果比较准确,但所费人力、物力和时间较多,而抽样调查得到的结果比较近似进行解答即可.
解:调查某品牌护眼灯的使用寿命,具有破坏性,适合采用的调查方式是抽样调查,
故答案为:抽样调查.

12. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
根据圆锥的体积= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ×底面积×高,即可求解.
解:∵圆锥的底面半径为5,高为12
它的体积 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

13. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
由矩形的性质得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,从而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,由折叠的性质可得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,从而得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,由此推断出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
由折叠的性质可得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

14. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 13

【解析】
由已知可分三种情况:当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,此时 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,等式成立.
解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,此时 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,等式成立;
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 13

15. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
表得出所有等可能的结果数,再从中找到符合条件的结果数,然后再用概率公式求解即可.
解:根据题意列出表格如下:


思想政治

地理

化学

生物

思想政治


思想政治,地理

思想政治,化学

思想政治,生物

地理

地理,思想政治


地理,化学

地理,生物

化学

化学,思想政治

化学,地理


化学,生物

生物

生物,思想政治

生物,地理

生物,化学


由表格可得,共有12种等可能的结果,其中该同学恰好选择地理和化学两科的有2种结果,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 某同学从4门再选科目中随机选择2科,恰好选择地理和化学的概率为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

16. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
首先解不等式组求得解集,然后根据不等式组有三个整数解,确定整数解,则可以得到一个关于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的不等式组求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的范围.

解:解不等式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解不等式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 不等式组有三个整数解,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 不等式组的整数解为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 01
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

17. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
仿照阅读材料中的方法将原式展开,即可得出结果.
根据题意得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 展开后系数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
系数和: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 展开后系数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
系数和: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 展开后系数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
系数和: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

18.①②③

【解析】
延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,并截取 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即可判断①正确;根据三角形中位线性质得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,判断②正确;根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据四边形内角和得出
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,判断③正确;根据②可知, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据勾股定理得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,判断④错误.
解:延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,并截取 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,如图所示:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
根据旋转可知, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 面积相同,故①正确;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的中位线,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,故②正确;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,故③正确;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
根据②可知, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为中线,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,故④错误;
综上分析可知,正确的是①②③.

19.1

【解析】
首先去绝对值符号、代入特殊角的三角函数值以及负整数幂的运算,然后进行加减法.
解:原式=﹣1+ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ﹣2× <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> +2
=﹣1+ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> +2
=1

20. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
先通分,再计算加减,再把 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 代入进行计算即可.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时,原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

21. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
设第一批足球单价为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 元,则第二批足球单价为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 元,再根据题意列出分式方程即可.
设第一批足球单价为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 元,则第二批足球单价为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 元,
由题意得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
经检验: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是原分式方程的解,且符合题意,
则第二批足球单价为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
该学校两批共购买了 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
答:该学校两批共购买了 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 个.

22.垂直高度 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 约为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为矩形,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中利用正弦函数求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 长度,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,可以求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 长度,即可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解:过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (米),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米.
答:垂直高度 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 约为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 米.

23.(1)4025
(2)7
(3)
我校获“志愿者勋章”的学生人数是700

【解析】
1)直接根据条形统计图和扇形统计图中的数据进行计算即可;
2)根据平均数的定义进行计算即可得到答案;
3)先求出本学期参加志愿服务不少于7次的学生人数所占的百分比,再乘以1000,即可得到答案.
1)解:根据题意可得:
本次接受调查的学生人数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (人),
扇形统计图中的 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为:4025
2)解:根据题意可得:
所调查的学生本学期参加志愿服务次数的平均数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (次);
3)解:根据题意得:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (人),
答:我校获“志愿者勋章”的学生人数是700人.

24.(1)证明,见解析
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
1)根据平行四边形的性质,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据平行线的性质,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;再根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的中点,全等三角形的判定,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据矩形的判定,即可;
2)过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据勾股定理,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的长,再根据四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的面积等于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即可.
1)∵四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是平行四边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是平行四边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
平行四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是矩形.
2)过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是平行四边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的面积等于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是对角线的中心,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
平行四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的面积为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

25.(1)一次函数的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</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/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
1)把 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 分别代入一次函数和反比例函数求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值即可得到答案;
2)联立 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 求出点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的坐标,令直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,由直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 求出点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的坐标,最后由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,进行计算即可得到答案;
3)直接由函数图象即可得到答案.
1)解:把 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 代入一次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 一次函数的解析式为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 代入反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</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/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
2)解:联立 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
令直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,如图,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
3)解:由图象可得:
    <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的上方时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的取值范围为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

26.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时,窗户透过的光线最多(窗户的面积最大),最大面积为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
1)由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 可表示出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的长,由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 可表示出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的长,进而可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 之间的函数关系式;
2)根据(1)中相关数据列出函数解析式,然后利用函数的性质解答.
1)∵四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 分别是边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
2)设面积为S
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时,窗户透过的光线最多(窗户的面积最大),最大面积为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

27.(1)证明,见解析
(2)
证明,见解析
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
1)连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据平行线的判定和性质,即可;
2)由(1)得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,相似三角形的判定和性质,即可;
3)根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的半径为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,再根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,在根据勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即可.
1)连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的切线.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>    
2)证明,如下:
由(1)得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
3)∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的半径为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

28.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
1)利用待定系数法求出二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的表达式即可;
2)连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,过点R <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的延长线于点M,分别表示出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的长,根据正切的定义即可得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值;
3)分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 两种情况讨论求解即可.
1)解:由表格可知,二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的图象经过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 得到
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
2)如图,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,过点R <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的延长线于点M
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的横坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
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/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
P与点Q关于直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 对称,
设点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
P的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
3)由表格可知点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
将线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 先向上平移3个单位长度,再向右平移1个单位长度,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
由题意可得,二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,与线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 只有一个交点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时,抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 开口向上,顶点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 下方,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
此时满足题意,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时,抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 开口向下,顶点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 上时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
此时满足题意,
将点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
将点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,此时满足题意,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
综上可知,  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/974/" title="大庆" class="c1" target="_blank">大庆</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>