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【327830】2023年湖南省张家界市中考数学真题

时间:2025-01-20 20:23:56 作者: 字数:18436字
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2023年湖南省张家界市中考数学真题

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评卷人

得分




一、选择题

1. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的相反数是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
C
2023
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

2.如图是由5个完全相同的小正方体组成的立体图形,其主视图是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

3.下列运算正确的是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

4.下列说法正确的是(       
A
.扇形统计图能够清楚地反映事物的变化趋势
B
.对某型号电子产品的使用寿命采用全面调查的方式
C
.有一种游戏的中奖概率是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,则做5次这样的游戏一定会有一次中奖
D
.甲、乙两组数据的平均数相等,它们的方差分别是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,则乙比甲稳定

5.如图,已知直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的度数是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

6.《四元玉鉴》是一部成就辉煌的数学名著,是宋元数学集大成者,也是我国古代水平最高的一部数学著作.该著作记载了“买椽多少”问题:“六贯二百一十钱,倩人去买几株椽.每株脚钱三文足,无钱准与一株椽”.大意是:现请人代买一批椽,这批椽的总售价为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 文.如果每株椽的运费是3文,那么少拿一株椽后,剩下的椽的运费恰好等于一株椽的价钱,试问 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 文能买多少株椽?设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 元购买椽的数量为x株,则符合题意的方程是(       ).
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

7.莱洛三角形”也称为圆弧三角形,它是工业生产中广泛使用的一种图形.如图,分别以等边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的三个顶点为圆心,以边长为半径画弧,三段圆弧围成的封闭图形是“莱洛三角形”.若等边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的边长为3,则该“莱洛三角形”的周长等于(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

8.如图,矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的顶点AC分别在y轴、x轴的正半轴上,点D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 上,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的图象经过点D及矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的对称中心M,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> .若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的面积为3,则k的值为(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
A2
B
3
C
4
D
5

评卷人

得分




二、填空题

9.仙境张家界,峰迷全世界”,据统计,2023年“五一”节假日期间,张家界市各大景区共接待游客约864000人次.将数据864000用科学计数法表示为______

10.因式分解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ______

11.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/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 有两个不相等的实数根,则m的取值范围是_____________

12.2023424日是我国第八个“中国航天日”,某校开展了一次航天知识竞赛,共选拔8名选手参加总决赛,他们的决赛成绩分别是9592938994909688.则这8名选手决赛成绩的中位数是______

13.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的平分线,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,将四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 绕点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 逆时针方向旋转后,得到四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,则四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 旋转的角度是______
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    

14.如图,在平面直角坐标系中,四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是正方形,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是以点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为半径的圆弧; <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是以点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为半径的圆弧, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是以点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为半径的圆弧, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是以点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为圆心, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为半径的圆弧,继续以点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为圆心按上述作法得到的曲线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 称为正方形的“渐开线”,则点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的坐标是_______
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

评卷人

得分




三、解答题

15.计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

16.先化简 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,然后从 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 12这三个数中选一个合适的数代入求值.

17.为拓展学生视野,某中学组织八年级师生开展研学活动,原计划租用45座客车若干辆,但有15人没有座位;若租用同样数量的60座客车,则多出三辆车,且其余客车恰好坐满.现有甲、乙两种客车,它们的载客量和租金如下表所示:


甲型客车

乙型客车

载客量(人/辆)

45

60

租金(元/辆)

200

300

(1)参加此次研学活动的师生人数是多少?原计划租用多少辆45座客车?
(2)
若租用同一种客车,要使每位师生都有座位,应该怎样租用才合算?

18.如图,已知点ADCB在同一条直线上,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
(1)求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 时,求证:四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是菱形.

19.2022421日新版《义务教育课程方案和课程标准(2022年版)》正式颁布,优化了课程设置,其中将劳动教育从综合实践活动课程中独立出来.某校为了初步了解学生的劳动教育情况,对九年级学生“参加家务劳动的时间”进行了抽样调查,并将劳动时间x分为如下四组(A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,单位:分钟)进行统计,绘制了如下不完整的统计图.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
根据以上信息,解答下列问题:
(1)
本次抽取的学生人数为______人,扇形统计图中m的值为______
(2)
补全条形统计图;
(3)
已知该校九年级有600名学生,请估计该校九年级学生中参加家务劳动的时间在80分钟(含80分钟)以上的学生有多少人?
(4)
D组中有3名女生,其余均是男生,从中随机抽取两名同学交流劳动感受,请用列表法或树状图法,求抽取的两名同学中恰好是一名女生和一名男生的概率.

20.游张家界山水,逛七十二奇楼”成为今年旅游新特色.某数学兴趣小组用无人机测量奇楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的高度,测量方案如图:先将无人机垂直上升至距水平地面225mP点,测得奇楼顶端A的俯角为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,再将无人机沿水平方向飞行200m到达点Q,测得奇楼底端B的俯角为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,求奇楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的高度.(结果精确到1m,参考数据: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>     <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    

21.阅读下面材料:
将边长分别为a <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的正方形面积分别记为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
例如:当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
根据以上材料解答下列问题:
(1)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ______ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ______
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 时,把边长为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的正方形面积记作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,其中n是正整数,从(1)中的计算结果,你能猜出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 等于多少吗?并证明你的猜想;
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 时,令 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,…, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,求T的值.

22.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的外接圆, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的直径, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 延长线上一点,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
(1)
求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的切线;
(2)
若直径 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的长.

23.如图,在平面直角坐标系中,已知二次函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的图象与x轴交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 和点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 两点,与y轴交于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> .点D为线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 上的一动点.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
(1)求二次函数的表达式;
(2)
如图1,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 周长的最小值;
(3)
如图2,过动点D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 交抛物线第一象限部分于点P,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,记 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的面积和为S,当S取得最大值时,求点P的坐标,并求出此时S的最大值.

参考答案

1.B

【解析】
根据相反数的定义求解即可,只有符号不同的两个数互为相反数.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的相反数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故选:B

2.D

【解析】
根据从正面看得到的图形是主视图,可得答案.
解:其主视图有2列,从左到右依次有31个正方形,图形如下:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
故选D

3.C

【解析】
根据完全平方公式及合并同类项、积的乘方运算依次判断即可.
解:A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,选项计算错误,不符合题意;
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,选项计算错误,不符合题意;
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,计算正确,符合题意;
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,选项计算错误,不符合题意;
故选:C

4.D

【解析】
根据扇形统计图的特点、全面调查及抽样调查的特点,概率的意义及方差的意义依次判断即可.
解:A、扇形统计图能够清楚地反映事物所占的比例,选项错误,不符合题意;
B
、对某型号电子产品的使用寿命调查有破坏性,适合采用抽样调查,选项错误,不符合题意;
C
、有一种游戏的中奖概率是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,则做5次这样的游戏不一定会中奖,选项错误,不符合题意;
D
、平均数相等,方差越小,越稳定,选项正确,符合题意;
故选:D

5.A

【解析】
根据平行线的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,推得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,根据角平分线的性质可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的度数,即可求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的度数.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故选:A

6.C

【解析】
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 元购买椽的数量为x株,根据单价 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 总价 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 数量,求出一株椽的价钱为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,再根据少拿一株椽后剩下的椽的运费恰好等于一株椽的价钱,即可列出分式方程,得到答案.
解:设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 元购买椽的数量为x株,则一株椽的价钱为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
由题意得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故选C

7.B

【解析】
根据等边三角形的性质及弧长公式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 求解即可.
解:∵等边三角形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的边长为3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
该“莱洛三角形”的周长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故选:B

8.C

【解析】
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,根据矩形对称中心的性质得出延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 恰好经过点B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,确定 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,然后结合图形及反比例函数的意义,得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,代入求解即可.
解:∵四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的对称中心M
延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 恰好经过点B <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
D <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 上,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 在反比例函数的图象上,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故选C

9. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
科学记数法的表示形式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的形式,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为整数.确定 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的值时,要看把原数变成 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 时,小数点移动了多少位, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的绝对值与小数点移动的位数相同.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

10. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
先提取公因式,然后利用完全平方公式因式分解即可.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

11.m-1

【解析】
根据有两个不相等的实数根得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 0,解不等式即可.
解:根据题意,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 0
解得 m-1
故答案为m-1

12.92.5

【解析】
将成绩按照从小到大顺序排列后,根据中位数的定义即可得到答案.
解:将决赛成绩从小到大顺序排列为8889909293949596
中位数为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故答案为:92.5

13. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
根据角平分线的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,根据旋转的性质可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,求得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,即可求得旋转的角度.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的平分线, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
将四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 绕点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 逆时针方向旋转后,得到四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

14. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
将四分之一圆弧对应的A点坐标看作顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,再根据A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的坐标找到规律即可.
A点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> A点绕B点顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 所得,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点绕O点顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 所得,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点绕C点顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 所得,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点绕A点顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 所得,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
由此可得出规律: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为绕BOCA四点作为圆心依次循环顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,且半径为123 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> n,每次增加1
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为以点C为圆心,半径为2022 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 顺时针旋转 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 所得
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

15. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
先化简绝对值,零次幂及特殊角的三角函数、负整数指数幂,然后计算加减法即可.
解:原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

16. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
根据分式的运算法则先化简,然后再由分式有意义的条件代入求值即可.
解:原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

17.(1)参加此次研学活动的师生有600人,原计划租用45座客车13
(2)
1445座客车较合算

【解析】
1)设参加此次研学活动的师生有x人,原计划租用45座客车y辆,根据题意列出二元一次方程组求解即可;
2)由(1)结论求出所需费用比较即可.
1)解:设参加此次研学活动的师生有x人,原计划租用45座客车y
依题意得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
答:参加此次研学活动的师生有600人,原计划租用45座客车13辆;
2)∵要使每位师生都有座位,
45座客车14辆,则租60座客车10辆,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
1445座客车较合算.

18.(1)见解析
(2)
见解析

【解析】
1)根据题意得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,再由全等三角形的判定和性质及平行线的判定证明即可;
2)方法一:利用全等三角形的判定和性质得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,又 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,再由菱形的判定证明即可;方法二:利用(1)中结论得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,结合菱形的判定证明即可.
1)证明:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
2)方法一:在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,又 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是平行四边形
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是菱形;
方法二:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是平行四边形
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 是菱形.

19.(1)5030
(2)
见解析
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
(4)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
1)由D组人数及所占百分比得出总人数,然后利用B组人数除以总人数即可得出结果;
2)用总人数减去各组人数得出C组人数,然后补全统计图即可;
3)总人数乘以CD组所占比例即可;
4)方法一、利用列表法求概率;方法二、利用树状图法求概率即可.
1)解:根据题意得,本次抽取的人数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 人,
B组人数为15人,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
故答案为:5030
2)解:C组人数为:50-10-15-5=20人,
补全统计图如图所示:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
3)解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> (人),
答:估计该校九年级学生中参加家务劳动的时间在80分钟(含80分钟)以上的学生有300人;
4)方法一:列表法:


1

2

3

1

2

1


(女1,女2

(女1,女3

(女1,男1

(女1,男2

2

(女2,女1


(女2,女3

(女2,男1

(女2,男2

3

(女3,女1

(女3,女2


(女3,男1

(女3,男2

1

(男1,女1

(男1,女2

(男1,女3


(男1,男2

2

(男2,女1

(男2,女2

(男2,女3

(男2,男1


共有20种等可能结果,其中满足条件的有12种,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> .
方法二:树状图法:如图,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
共有20种等可能结果,其中满足条件的有12种,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

20. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的延长线于点C,根据题意得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,再由等腰直角三角形得出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,然后解直角三角形即可.
解:延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的延长线于点C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
由题意得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
奇楼的高度 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 约为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

21.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
(2)
猜想结论: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,证明见解析
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
1)根据题意,直接代入然后利用完全平方公式展开合并求解即可;
2)根据题意得出猜想,然后由完全平方公式展开证明即可;
3)结合题意利用(2)中结论求解即可.
1)解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 时,
原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 时,
原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
2)猜想结论: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
证明: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

22.(1)详见解析
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
(1)
根据直径所对的圆周角是直角,余角的性质即可求得结论;
(2)
根据已知条件可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,再根据正切的定义和相似三角形的性质得到线段的关系即可求得线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的长度.
1)证明:连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的直径,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的切线;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
2)解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> (取正值),
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

23.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>

【解析】
1)根据题意设抛物线的表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,将 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 代入求解即可;
2)作点O关于直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的对称点E,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,根据点坐特点及正方形的判定得出四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为正方形, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,连接AE,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 于点D,由对称性 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,此时 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 有最小值为AE的长,再由勾股定理求解即可;
3)由待定系数法确定直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,然后结合图形及面积之间的关系求解即可.
1)解:由题意可知,设抛物线的表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 代入上式得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
所以抛物线的表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
2)作点O关于直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的对称点E,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
OE关于直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 对称,
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 为正方形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 于点D,由对称性 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
此时 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 有最小值为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的长,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的周长为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的最小值为10
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的周长的最小值为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>    
3)由已知点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
同理可得:直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
设直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
由(1)设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,代入直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的表达式
得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 的表达式为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> ,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
PD都在第一象限,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> 时,此时P点为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a> .
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/982/" title="湖南省" class="c1" target="_blank">湖南省</a> <a href="/tags/1043/" title="张家界" class="c1" target="_blank">张家界</a> <a href="/tags/1121/" title="湖南" class="c1" target="_blank">湖南</a>