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【327886】2023年四川省南充市中考数学真题

时间:2025-01-20 20:35:26 作者: 字数:21460字
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2023年四川省南充市中考数学真题

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一、选择题

1.如果向东走10m记作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,那么向西走 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 记作(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

2.如图,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 沿 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 向右平移得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
A2
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
3
D
5

3.某女鞋专卖店在一周内销售了某种女鞋60双,对这批鞋子尺码及销量进行统计,得到条形统计图(如图).根据图中信息,建议下次进货量最多的女鞋尺码是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
A22cm
B
22.5cm
C
23cm
D
23.5cm

4.如图,小兵同学从 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处出发向正东方向走 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 米到达 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处,再向正北方向走到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处,已知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 两处相距(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

5.《孙子算经》记载:“今有木,不知长短.引绳度之,余绳四尺五寸;屈绳量之,不足一尺.木长几何?”(尺、寸是长度单位,1尺=10寸).意思是,现有一根长木,不知道其长短.用一根绳子去度量长木,绳子还剩余4.5尺;将绳子对折再度量长木,长木还剩余1尺.问长木长多少?设长木长为x尺,则可列方程为(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

6.如图,数学活动课上,为测量学校旗杆高度,小菲同学在脚下水平放置一平面镜,然后向后退(保持脚、镜和旗杆底端在同一直线上),直到她刚好在镜子中看到旗杆的顶端.已知小菲的眼睛离地面高度为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,同时量得小菲与镜子的水平距离为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,镜子与旗杆的水平距离为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则旗杆高度为(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

7.若点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> )上,则下列各点在抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上的是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

8.如图,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,以点A为圆心,适当长为半径画弧,分别交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 于点MN,再分别以MN为圆心,大于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长为半径画弧,两弧在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的内部相交于点P,画射线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 交于点D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,垂足为E.则下列结论错误的是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

9.关于xy的方程组 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的解满足 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值是(       
A
1
B
2
C
4
D
8

10.抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x轴的一个交点为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则实数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的取值范围是(       )
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

评卷人

得分




二、填空题

11.若分式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值为0,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值为________

12.不透明袋中有红、白两种颜色的小球,这些球除颜色外无其他差别.从袋中随机取出一个球是红球的概率为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,若袋中有4个白球,则袋中红球有________个.

13.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的直径,点DM分别是弦 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,弧 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的中点, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长是________
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    

14.小伟用撬棍撬动一块大石头,已知阻力和阻力臂分别为1000N0.6m,当动力臂由1.5m增加到2m时,撬动这块石头可以节省________N的力.(杠杆原理:阻力 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 阻力臂 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 动力 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 动力臂)

15.如图,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> k为常数, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> )与xy轴分别交于点AB,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值是________
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    

16.如图,在等边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,过点C作射线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,点MN分别在边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 沿 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 折叠,使点B落在射线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上的点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,已知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .给出下列四个结论:① <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为定值;②当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为菱形;③当点NC重合时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ;④当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 最短时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .其中正确的结论是________(填写序号)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

评卷人

得分




三、解答题

17.先化简,再求值: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

18.如图,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在对角线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .求证:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

19.为培养学生劳动习惯,提升学生劳动技能,某校在五月第二周开展了劳动教育实践周活动.七(1)班提供了四类活动:A.物品整理,B.环境美化,C.植物栽培,D.工具制作.要求每个学生选择其中一项活动参加,该班数学科代表对全班学生参与四类活动情况进行了统计,并绘制成统计图(如图).
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
已知该班有15人参加A类活动,则参加C类活动有多少人?
(2)
该班参加D类活动的学生中有2名女生和2名男生获得一等奖,其中一名女生叫王丽,若从获得一等奖的学生中随机抽取两人参加学校“工具制作”比赛,求刚好抽中王丽和1名男生的概率.

20.已知关于x的一元二次方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
求证:无论m为何值,方程总有实数根;
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是方程的两个实数根,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,求m的值.

21.如图,一次函数图象与反比例函数图象交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,与x轴交于点C,与y轴交于点D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
求反比例函数与一次函数的解析式;
(2)
Mx轴上,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,求点M的坐标.

22.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 相切于点A,半径 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 相交于点D,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
(1)求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长.

23.某工厂计划从AB两种产品中选择一种生产并销售,每日产销x件.已知A产品成本价m/件(m为常数,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,售价8/件,每日最多产销500件,同时每日共支付专利费30元;B产品成本价12/件,售价20/件,每日最多产销300件,同时每日支付专利费y元,y(元)与每日产销x(件)满足关系式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
若产销AB两种产品的日利润分别为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元,请分别写出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x的函数关系式,并写出x的取值范围;
(2)
分别求出产销AB两种产品的最大日利润.(A产品的最大日利润用含m的代数式表示)
(3)
为获得最大日利润,该工厂应该选择产销哪种产品?并说明理由.(利润 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (售价 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 成本) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 产销数量 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 专利费)

24.如图,正方形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的中点,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
(1)求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 绕点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 逆时针旋转,使点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的对应点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 落在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .当点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上运动时(点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 不与 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 重合),判断 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的形状,并说明理由.
(3)
在(2)的条件下,已知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长.

25.如图1,抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> )与 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴交于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 两点,与 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(1)
求抛物线的解析式;
(2)
P在抛物线上,点Qx轴上,以BCPQ为顶点的四边形为平行四边形,求点P的坐标;
(3)
如图2,抛物线顶点为D,对称轴与x轴交于点E,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的直线(直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 除外)与抛物线交于GH两点,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 分别交x轴于点MN.试探究 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是否为定值,若是,求出该定值;若不是,说明理由.

参考答案

1.C

【解析】
根据具有相反意义的量即可得.
解:因为向东与向西是一对具有相反意义的量,
所以如果向东走10m记作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,那么向西走 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 记作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:C

2.A

【解析】
利用平移的性质得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即可得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长.
解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 沿 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 方向平移至 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:A

3.D

【解析】
进货量最多的应该是销量最多的,故求出众数即可.
专卖店进货量最多的应该是销量最多的,根据条形统计图可得,众数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,故下次进货最多的女鞋尺码是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:D

4.B

【解析】
根据锐角三角函数中余弦值的定义即可求出答案.
解:小兵同学从 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处出发向正东方向走 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 米到达 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处,再向正北方向走到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
故选: B .

5.A

【解析】
设长木长为x尺,则绳子长为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 尺,根据“将绳子对折再度量长木,长木还剩余1尺”,可列出方程.
设长木长为x尺,则绳子长为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 尺,根据题意,得
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:A

6.B

【解析】
根据镜面反射性质,可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再利用垂直求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,最后根据三角形相似的性质,即可求出答案.
解:如图所示,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
由图可知, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 根据镜面的反射性质,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 小菲的眼睛离地面高度为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,同时量得小菲与镜子的水平距离为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,镜子与旗杆的水平距离为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
故选:B.

7.D

【解析】
观察抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 和抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 可以发现,它们通过平移得到,故点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 通过相同的平移落在抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上,从而得到结论.
抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> )向左平移1个单位长度得到
抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 向左平移1个单位长度后,会在抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:D

8.C

【解析】
由作图方法可知, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的角平分线,则由角平分线的定义和性质即可判定AB;利用勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,利用等面积法求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,由此求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可判断CD
解:由作图方法可知, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的角平分线,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,故A结论正确,不符合题意;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,故B结论正确,不符合题意;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,由勾股定理得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,故C结论错误,符合题意;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,故D结论正确,不符合题意;
故选C

9.D

【解析】
法一:利用加减法解方程组,用 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 表示出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再将求得的代数式代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的关系,最后将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 变形,即可解答.
法二: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入代数式进行求解即可.
解:法一: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
法二: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:D

10.B

【解析】
根据抛物线有交点,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 有实数根,得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,分类讨论,分别求得当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的范围,即可求解.
解:∵抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x轴有交点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 有实数根,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,如图所示,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
依题意,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
综上所述, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:B

11. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
根据分式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值为0,得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,求解即可得到答案.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 分式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值为0
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

12.6

【解析】
设袋中红球有x个,然后根据概率计算公式列出方程求解即可.
解:设袋中红球有x个,
由题意得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
检验,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是原方程的解,
袋中红球有6个,
故答案为:6

13.4

【解析】
根据圆周角定理得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再由勾股定理确定 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,半径为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,利用垂径定理确定 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再由勾股定理求解即可.
解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的直径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
DM分别是弦 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,弧 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故答案为:4

14.100

【解析】
设动力为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,根据阻力 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 阻力臂 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 动力 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 动力臂,分别解得动力臂在1.5m2m时的动力,即可解答.
解:设动力为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
根据阻力 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 阻力臂 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 动力 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 动力臂,
当动力臂在1.5m时,可得方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
当动力臂在2m时,可得方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,故节省100N的力,
故答案为:100

15.1

【解析】
根据一次函数解析式得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,然后代入化简即可.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故答案为:1

16.①②④

【解析】
根据等边三角形的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,根据折叠的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,由此即可判断①正确;先解直角三角形可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,从而可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,然后根据平行线的判定可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,根据菱形的判定即可得②正确;先根据折叠的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,从而可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再根据等腰三角形的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,然后根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可判断③错误;当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 最短时,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,先利用勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,根据折叠的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再利用勾股定理可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,然后根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 建立方程,解一元二次方程可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值,由此即可判断④正确.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是等边三角形,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
由折叠的性质得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,是定值,则结论①正确;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
由折叠的性质得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为平行四边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为菱形,则结论②正确;
如图,当点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 重合时,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
由折叠的性质得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则结论③错误;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 最短时,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
如图,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
由折叠的性质得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (不符合题意,舍去),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则结论④正确;
综上,正确的结论是①②④,
故答案为:①②④.

17. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
先用平方差公式、完全平方公式展开,再去括号、合并同类项进行化简,最后代入求值.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

18.(1)证明见解析
(2)
证明见解析

【解析】
1)根据平行四边形的性质推出相应的线段和相应的角度相等,再利用已知条件求证 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,最后证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可求出答案.
2)根据三角形全等证明角度相等,再利用邻补角定义推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可证明两直线平行.
1)证明: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为平行四边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2)证明:由(1)得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

19.(1)10
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)根据A类人数及占比得出总人数,然后乘以C所占比例即可;
2)令王丽为女1,另外的女生为女2,男生分别为男1,男2,根据画树状图求概率即可求解.
1)解:这次被调查的学生共有 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (人)
参加C类活动有: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (人)
参加C类活动有10人;
2)解:令王丽为女1,另外的女生为女2,男生分别为男1,男2
画树状图为:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
共有12种等可能结果,符合题意的有4种,
恰好选中王丽和1名男生的概率为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

20.(1)见解析
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)根据一元二次方程根的情况与判别式的关系,只要判定 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可得到答案;
2)根据一元二次方程根与系数的关系得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,整体代入得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 求解即可得到答案.
1)证明: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 关于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的一元二次方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
不论 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为何值,方程总有实数根;
2)解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是关于x的一元二次方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的两个实数根,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,整理,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
m的值为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

21.(1)反比例函数解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</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/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(2)
M点的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)设反比例函数解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,根据待定系数法,即可得到反比例函数解析式,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入求得的反比例函数,解得a的值,得到B点坐标,最后根据待定系数法即可求出一次函数解析式;
2)求出点C的坐标,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,分两种情况:MO点左侧;M点在O点右侧,根据三角形面积公式即可解答.
1)解:设反比例函数解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</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/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
经检验, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是方程的解,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
设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/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</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/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2)解:当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
MO点左侧时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
M点在O点右侧时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
综上,M点的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

22.(1)见解析
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,根据切线的性质得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再由平行线的性质得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,利用圆周角定理及等腰直角三角形的性质即可证明;
2)过点A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,过点C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的延长线于点F,根据勾股定理及等腰直角三角形的性质得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再由正切函数确定 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再由正方形的判定和性质及相似三角形的判定和性质求解即可.
1)证明:连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,如图所示:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 相切于点A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2)过点A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,过点C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的延长线于点F,如图所示:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
由(1)得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为等腰直角三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
由(1)得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为正方形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

23.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,该工厂应该选择产销A产品能获得最大日利润;当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,该工厂应该选择产销任一产品都能获得最大日利润;当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,该工厂应该选择产销B产品能获得最大日利润,理由见解析

【解析】
1)根据题木所给的利润计算公式求解即可;
2)根据(1)所求利用一次函数和二次函数的性质求解即可;
3)比较(2)中所求AB两种产品的最大利润即可得到答案.
1)解:由题意得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2)解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x增大而增大,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 最大,最大为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x增大而增大,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 最大,最大为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元;
3)解:当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,该工厂应该选择产销A产品能获得最大日利润;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,该工厂应该选择产销任一产品都能获得最大日利润;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,该工厂应该选择产销B产品能获得最大日利润;
综上所述,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,该工厂应该选择产销A产品能获得最大日利润;当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,该工厂应该选择产销任一产品都能获得最大日利润;当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,该工厂应该选择产销B产品能获得最大日利润.

24.(1)见解析
(2)
等腰直角三角形,理由见解析
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)根据正方形的基本性质以及“斜中半定理”等推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即可证得结论;
2)由旋转的性质得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,从而利用等腰三角形的性质推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再结合正方形对角线的性质推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即可证得结论;
3)结合已知信息推出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,从而利用相似三角形的性质以及勾股定理进行计算求解即可.
1)证:∵四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为正方形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的中点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2)解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为等腰直角三角形,理由如下:
由旋转的性质得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为等腰直角三角形;
3)解:如图所示,延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (不合题意,舍去),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    

25.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(3)
定值,理由见详解

【解析】
1)将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 两点代入抛物线的解析式即可求解;
2)根据PQ的不确定性,进行分类讨论:①过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,交抛物线于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,可求解;②在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴的负半轴上取点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,交抛物线于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,同时使 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即可求解;③当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为平行四边形的对角线时,在①中,只要点Q在点B的左边,且满足 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,也满足条件,只是点P的坐标仍是①中的坐标;
3)可设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,可求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再求直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,从而可求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,同理可求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即可求解.
1)解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> x轴交于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 两点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故抛物线的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2)解:①如图,过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,交抛物线于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是平行四边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
如图,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴的负半轴上取点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,交抛物线于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,同时使 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是平行四边形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
如上图,根据对称性: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为平行四边形的对角线时,由①知,点Q在点B的左边,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,也满足条件,此时点P的坐标仍为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
综上所述: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
3)解:是定值,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
理由:如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 经过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 可设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在抛物线上,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 可设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
整理得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则有
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
同理可求: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 对调位置后,同理可求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的定值为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1079/" title="南充" class="c1" target="_blank">南充</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>