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【327880】2023年四川省广安市中考数学真题

时间:2025-01-20 20:34:26 作者: 字数:21903字
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2023年四川省广安市中考数学真题

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得分




一、选择题

1.6的绝对值是(   
A
-6
B
6
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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

2.下列运算中,正确的是(  )
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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

3.2023年以来,广安市全面落实市委、市政府关于促进消费的各项政策措施,积极优化消费运行环境,消费加速回升. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 月,全市实现社会消费品总额116亿元,同比增长 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .请将116亿用科学记数法表示(  )
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

4.如图,由5个大小相同的小正方体搭成的几何体,它的俯视图是(  )
 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    

5.下列说法正确的是(  )
A
.三角形的一个外角等于两个内角的和
B
.对角线相等且互相垂直的四边形是正方形
C
.在一组数据1197868128中,众数和中位数都是8
D
.甲乙两组各10名同学参加“安全知识竞赛”,若两组同学的平均成绩相同,甲组的方差 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,乙组的方差 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则甲组同学的成绩比乙组同学的成绩稳定

6.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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为常数,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在第四象限,则关于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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的根的情况为(       )
A
.有两个相等的实数根
B
.有两个不相等的实数根
C
.没有实数根
D
.无法判定

7.如图,用弹簧测力计将一铁块悬于盛有水的水槽中,然后匀速向上提起,使铁块完全露出水面,并上升一定高度,则下列能反映弹簧测力计的读数y(单位:N)与铁块被提起的时间x(单位:s)之间的函数关系的大致图象是(  )
 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    

8.为了降低成本,某出租车公司实施了“油改气”措施.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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 分别表示燃油汽车和燃气汽车所需费用 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (单位:元)与行驶路程 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (单位:千米)的关系,已知燃油汽车每千米所需的费用比燃气汽车每千米所需的费用的3倍少0.1元,设燃气汽车每千米所需的费用为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元,则可列方程为(  )
 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

9.如图,在等腰直角 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,以点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为半径画弧,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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,以点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为半径画弧,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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则图中阴影部分的面积是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

10.如图所示,二次函数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的图象与 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .有下列结论: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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ;②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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 均在抛物线上,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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ;④ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .其中正确的有(  )
 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
A1
B
2
C
3
D
4

评卷人

得分




二、填空题

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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的平方根是_______

12.函数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中,自变量x的取值范围是__________

13.定义一种新运算:对于两个非零实数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值是___________

14.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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 内接于 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,圆的半径为7 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则弦 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长度为___________
 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    

15.如图,圆柱形玻璃杯的杯高为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,底面周长为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,在杯内壁离杯底 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处有一滴蜂蜜,此时,一只蚂蚁正好在杯外壁上,它在离杯上沿 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,且与蜂蜜相对的点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处,则蚂蚁从外壁 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处到内壁 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处所走的最短路程为___________ <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .(杯壁厚度不计)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    

16.在平面直角坐标系中,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴的正半轴上,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在直线 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上,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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 均为等边三角形.则点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的纵坐标为___________
 <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/1108/" title="广安" class="c1" target="_blank">广安</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.计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

18.先化简 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再从不等式 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 中选择一个适当的整数,代入求值.

19.如图,在四边形 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,垂足分别为点 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .求证: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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    

20.如图,一次函数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> )的图象与反比例函数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的图象在第一象限交于点 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
(1)求一次函数和反比例函数的解析式.
(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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴上, <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为腰的等腰三角形,请直接写出点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的坐标.

21.双减”政策实施后,某校为丰富学生的课余生活,开设了A书法,B绘画,C舞蹈,D跆拳道四类兴趣班.为了解学生对这四类兴趣班的喜爱情况,随机抽取该校部分学生进行了问卷调查,并将调查结果整理后绘制成两幅不完整的统计图.请根据统计图信息回答下列问题.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
(1)本次抽取调查学生共有___________人,估计该校3000名学生喜爱“跆拳道”兴趣班的人数约为___________人.
(2)
请将以上两个统计图补充完整.
(3)
甲、乙两名学生要选择参加兴趣班,若他们每人从ABCD四类兴趣班中随机选取一类,请用画树状图或列表法,求两人恰好选择同一类的概率.

22.广安盐皮蛋”是小平故里的名优特产,某超市销售 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 两种品牌的盐皮蛋,若购买9 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋和6 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋共需390元;若购买5 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋和8 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋共需310元.
(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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋、 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋每箱价格分别是多少元?
(2)
若某公司购买 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 两种盐皮蛋共30箱,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种的数量至少比 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种的数量多5箱,又不超过 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种的2倍,怎样购买才能使总费用最少?并求出最少费用.

23.为了美化环境,提高民众的生活质量,市政府在三角形花园 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 边上修建一个四边形人工湖泊 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,并沿湖泊修建了人行步道.如图,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的正东方向170米处,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的正北方向,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 都在点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的正北方向, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 长为100米,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的北偏东 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 方向,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的北偏东 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 方向.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
(1)求步道 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长度.
(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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处有一个小商店,某人从点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 出发沿人行步道去商店购物,可以经点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 到达点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,也可以经点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 到达点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,请通过计算说明他走哪条路较近.结果精确到个位)(参考数据: <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

24.将边长为2的正方形剪成四个全等的直角三角形,用这四个直角三角形拼成符合要求的四边形,请在下列网格中画出你拼成的四边形(注:①网格中每个小正方形的边长为1;②所拼的图形不得与原图形相同;③四边形的各顶点都在格点上).
 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>      

25.如图,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的直角边 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为直径作 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,交斜边 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的切线.
(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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长.
(3)
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

26.如图,二次函数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的图象交 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴于点 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴于点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,对称轴是直线 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴上一动点, <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,交直线 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,交抛物线于点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
(1)求这个二次函数的解析式.
(2)
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 上运动(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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 与点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 、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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 不重合),求四边形 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 面积的最大值,并求出此时点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的坐标.
(3)
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴上运动,则在 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴上是否存在点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,使以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为顶点的四边形是菱形?若存在,请直接写出所有满足条件的点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的坐标;若不存在,请说明理由.

参考答案

1.B

【解析】
在数轴上,表示一个数的点到原点的距离叫做这个数的绝对值.
负数的绝对值等于它的相反数,所以-6的绝对值是6
故选:B

2.D

【解析】
根据合并同类项、同底数幂的乘法、完全平方公式、积的乘方与幂的乘方法则逐项判断即可得.
解:A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 不是同类项,不可合并,则此项错误,不符合题意;
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则此项错误,不符合题意;
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则此项错误,不符合题意;
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,则此项正确,符合题意;
故选:D

3.B

【解析】
根据科学记数法的定义即可得.
解:116亿 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:B

4.B

【解析】
根据俯视图的定义(从上面观察物体所得到的视图是俯视图)即可得.
解:这个几何体的俯视图是:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
故选:B

5.C

【解析】
根据三角形的外角定理,正方形的判定,众数和中位数的定义,方差的意义判断即可.
解:A.三角形的一个外角等于与它不相邻两个内角的和,故选项A错误;
B
.要加上 “对角线互相平分”这个条件,故选项B错误;
C
.这列数据从小到大排列为6788891112
8
出现了3次,故众数是8,中位数是 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选项C正确;
D
.方差越小,数据越稳定,故选项D错误.
故选:C

6.B

【解析】
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在第四象限,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,进而根据一元二次方程根的判别式 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即可求解.

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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在第四象限,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的判别式 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 有两个不相等的实数根.
故选:B

7.A

【解析】
根据浮力的知识,铁块露出水面前读数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 不变,出水面后 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 逐渐增大,离开水面后 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 不变.
解:由浮力知识得: <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,读数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
在铁块露出水面以前,浮力不变,则此过程中弹簧的读数不变,
当铁块慢慢露出水面开始,浮力减小,则拉力增加,弹簧的读数逐渐增大,
当铁块完全露出水面后,浮力等于0,拉力等于重力,弹簧的读数不变,
观察四个选项可知,只有选项A符合,
故选:A

8.D

【解析】
先求出燃油汽车每千米所需的费用为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元,再根据函数图象可得燃油汽车所需费用为25元时与燃气汽车所需费用为10元时,所行驶的路程相等,据此列出方程即可得.
解:由题意得:燃油汽车每千米所需的费用为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元,
由函数图象可知,燃油汽车所需费用为25元时与燃气汽车所需费用为10元时,所行驶的路程相等,
则可列方程为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:D

9.C

【解析】
先利用扇形的面积公式求出扇形 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 和扇形 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的面积,再减去 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的面积即可得.
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是等腰直角三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
图中阴影部分的面积是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故选:C

10.C

【解析】
根据二次函数图像的性质、二次函数图像与系数的关系以及与 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴交点问题逐项分析判断即可.
解:由图可知,二次函数开口方向向下,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴正半轴交于一点,
 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
故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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是关于二次函数对称轴对称,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在对称轴的左边, <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在对称轴的右边,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
故②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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 图象与 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
故③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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
故④不正确.
综上所述,正确的有①②③.
故选:C.

11.±2

【解析】
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的平方根是±2
故答案为±2

12.x≥-2x≠1

【解析】
根据二次根式有意义的条件和分式有意义的条件即可求出结论.
解:由题意可得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
解得x≥-2x≠1
故答案为:x≥-2x≠1

13. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
先根据 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 可得一个关于 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的等式,再根据新运算的定义代入计算即可得.
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

14. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,先根据圆周角定理可得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再根据等腰三角形的三线合一可得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,然后解直角三角形可得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长,由此即可得.
解:如图,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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
圆的半径为7
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

15.10

【解析】
如图(见解析),将玻璃杯侧面展开,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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的对称点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,根据两点之间线段最短可知 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长度即为所求,利用勾股定理求解即可得.
解:如图,将玻璃杯侧面展开,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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的对称点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 延长线于点 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
底面周长为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
由两点之间线段最短可知,蚂蚁从外壁 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处到内壁 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 处所走的最短路程为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故答案为:10

16. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,交直线 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴于点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,先求出 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再根据等边三角形的性质、等腰三角形的判定可得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,然后解直角三角形可得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长,即可得点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的纵坐标,同样的方法分别求出点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的纵坐标,最后归纳类推出一般规律,由此即可得.
解: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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,交直线 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴于点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是等边三角形,
 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,即点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的纵坐标为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
同理可得: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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的纵坐标为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的纵坐标为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的纵坐标为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
归纳类推得: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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的纵坐标为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为正整数),
则点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的纵坐标为 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
先计算有理数的乘方、零指数幂、特殊角的余弦值、化简绝对值,再计算乘法与加减法即可得.
解: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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

18. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,选择 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,式子的值为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (或选择 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,式子的值为1

【解析】
先计算括号内的分式减法,再计算分式的除法,然后根据分式有意义的条件选择适当的 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的值,代入计算即可得.
解: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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为整数,
 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 选择 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入得: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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
选择 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入得: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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

19.见详解

【解析】
先证明 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再证明  <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再由平行四边形的判定即可得出结论.
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是平行四边形.

20.(1)一次函数的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)根据待定系数法,把已知点代入再解方程即可得出答案;
2)首先利用勾股定理求出得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长,再分两种情形讨论即可.
1)解:把点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入一次函数 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
把点 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
把点 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
故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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 关于直线 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 对称,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
综上所述: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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

21.(1)60300
(2)
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)根据喜欢绘画的条形统计图和扇形统计图信息即可得本次抽取调查学生的总人数,再利用3000乘以喜欢跆拳道的学生所占百分比即可得;
2)先求出喜欢书法的学生人数,据此补全条形统计图,再求出喜欢舞蹈和跆拳道的学生所占百分比,据此补全扇形统计图即可得;
3)先画出树状图,从而可得甲、乙两名学生选择参加兴趣班的所有等可能的结果,再找出两人恰好选择同一类的结果,然后利用概率公式计算即可得.
1)解:本次抽取调查学生的总人数为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (人),
估计该校3000名学生喜爱“跆拳道”兴趣班的人数约为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (人),
故答案为:60300
2)解:喜欢书法的学生人数人 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (人),
喜欢舞蹈的学生所占百分比为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
喜欢跆拳道的学生所占百分比为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
则补全两个统计图如下:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
3)解:由题意,画树状图如下:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
由图可知,甲、乙两名学生选择参加兴趣班的所有等可能的结果共有16种,其中,两人恰好选择同一类的结果有4种,
则两人恰好选择同一类的概率为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
答:两人恰好选择同一类的概率为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

22.(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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋每箱价格是30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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋每箱价格是20
(2)
购买 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋18箱, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋12箱才能使总费用最少,最少费用为780

【解析】
1)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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋每箱价格是 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋每箱价格是 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元,根据题意建立方程组,解方程组即可得;
2)设购买 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 箱,则购买 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 箱,根据题意建立不等式组,解不等式组可得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的取值范围,再结合 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为正整数可得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 所有可能的取值,然后根据(1)的结果逐个计算总费用,找出总费用最少的购买方案即可.
1)解: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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋每箱价格是 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋每箱价格是 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 元,
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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
答: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋每箱价格是30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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋每箱价格是20元.
2)解:设购买 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 箱,则购买 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 箱,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 购买 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种的数量至少比 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种的数量多5箱,又不超过 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种的2倍,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为正整数,
 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 所有可能的取值为181920
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,购买总费用为 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,购买总费用为 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 时,购买总费用为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (元),
所以购买 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋18箱, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 种盐皮蛋12箱才能使总费用最少,最少费用为780元.

23.(1)200
(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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 这条路较近,理由见解析

【解析】
1)根据矩形的性质和锐角三角函数中的正弦值即可求出答案.
2)根据矩形的性质和锐角三角函数中的正切值、余弦值分别求出 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长度,比较 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可求出答案.
1)解:由题意得,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 垂直 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的延长线于点 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的正东方向170米处,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 在点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的正北方向,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 都在点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的正北方向,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 米,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
故答案为:200.
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 这条路较近,理由如下:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 米, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 米,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 结果精确到个位,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 这条路较近.
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 这条路较近.

24.见解析(答案不唯一,符合题意即可)

【解析】
根据轴对称图形和中心对称图形的性质进行作图即可.
解:①要求是轴对称图形但不是中心对称图形,则可作等腰梯形,如图四边形 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即为所求;
要求是中心对称图形但不是轴对称图形,则可作一般平行四边形,如图四边形 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即为所求;
要求既是轴对称图形又是中心对称图形,则可作菱形、矩形等,如图四边形 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即为所求;
要求既不是轴对称图形又不是中心对称图形,则考虑作任意四边形,如图四边形 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即为所求.
 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>    

25.(1)见详解
(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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
(3)
见详解

【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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,先根据直角三角形的性质,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再证明 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可;
2)由(1)中结论,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,先根据三角函数及勾股定理求出 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的长,再证明 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可;
3)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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 即可得出结论.
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的切线.
2)解:由(1)中结论,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
3)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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
由(1)中结论 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

26.(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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 最大值为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,此时 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>

【解析】
1)先根据二次函数对称轴公式求出 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,再把 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 代入二次函数解析式中进行求解即可;
2)先求出 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,求出直线 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ;再由 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,故当 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 最大,最大值为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,此时点P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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
3)分如图3-1,图3-2,图3-3,图3-4,图3-5,图3-6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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为对角线和边,利用菱形的性质进行列式求解即可.
1)解:∵二次函数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 的对称轴为直线 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
二次函数经过点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
二次函数解析式为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
2)解:∵二次函数经过点 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,且对称轴为直线 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
二次函数 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> y轴交于点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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 最大,最大值为 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
此时点P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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
3)解: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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为顶点的菱形的边;
如图3-1所示,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为对角线时,
        <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 是等腰直角三角形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,
C与点N关于抛物线对称轴对称,
N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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
如图3-2所示,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为边时,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
        <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
如图3-3所示,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为边时,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
        <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
同理可得 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
如图3-4所示,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为边时,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>        
同理可得 <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/1108/" title="广安" class="c1" target="_blank">广安</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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (舍去)或 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> (舍去);
如图3-5所示,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为对角线时,
 <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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>        
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,这与题意相矛盾,
此种情形不存在
如图3-6所示,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 为对角线时,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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 交于S
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>        
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> 轴,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a> ,这与三角形内角和为180度矛盾,
此种情况不存在;
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/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/1074/" title="四川省" class="c1" target="_blank">四川省</a> <a href="/tags/1108/" title="广安" class="c1" target="_blank">广安</a> <a href="/tags/1004/" title="四川" class="c1" target="_blank">四川</a>