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【327673】2022年海南省中考数学真题

时间:2025-01-20 19:58:09 作者: 字数:17692字
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2022年海南省中考数学真题

题号

总分

得分





注意事项:

1.答题前填写好自己的姓名、班级、考号等信息

2.请将答案正确填写在答题卡上



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/971/" title="海南" class="c1" target="_blank">海南</a> 的相反数是(   
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
B
2
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

2.为了加快构建清洁低碳、安全高效的能源体系,国家发布《关于促进新时代新能源高质量发展的实施方案》,旨在锚定到2030年我国风电、太阳能发电总装机容量达到1200000000千瓦以上的目标.数据1200000000用科学记数法表示为(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

3.若代数式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的值为6,则x等于(       
A
5
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C
7
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

4.如图是由5个完全相同的小正方体摆成的几何体,则这个几何体的主视图是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

5.在一次视力检查中,某班7名学生右眼视力的检查结果为:4.24.34.54.64.84.85.0,这组数据的中位数和众数分别是(       
A
5.04.6
B
4.65.0
C
4.84.6
D
4.64.8

6.下列计算中,正确的是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

7.若反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的图象经过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则它的图象也一定经过的点是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

8.分式方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的解是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

9.如图,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 是等边三角形,顶点B在直线n上,直线m <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点E,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点F,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的度数是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

10.如图,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,以点B为圆心,适当长为半径画弧,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点M,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点N,分别以点MN为圆心,大于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的长为半径画弧,两弧在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的内部相交于点P,画射线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点D,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的度数是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

11.如图,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,将线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 平移得到线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则点D的坐标是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

12.如图,菱形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中,点E是边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的中点, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 垂直 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的延长线于点F,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则菱形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的边长是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
A
3
B
4
C
5
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

评卷人

得分




二、填空题

13.因式分解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ___________

14.写出一个比 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 大且比 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 小的整数是___________

15.如图,射线AB与⊙O相切于点B,经过圆心O的射线AC与⊙O相交于点DC,连接BC,若∠A=40°,则∠ACB=___________ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

16.如图,正方形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中,点EF分别在边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ___________ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ;若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的面积等于1,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的值是___________
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

评卷人

得分




三、解答题

17.1)计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
2)解不等式组 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

18.我省某村委会根据“十四五”规划的要求,打造乡村品牌,推销有机黑胡椒和有机白胡椒.已知每千克有机黑胡椒比每千克有机白胡椒的售价便宜10元,购买2千克有机黑胡椒和3千克有机白胡椒需付280元,求每千克有机黑胡椒和每千克有机白胡椒的售价.

19.某市教育局为了解“双减”政策落实情况,随机抽取几所学校部分初中生进行调查,统计他们平均每天完成作业的时间,并根据调查结果绘制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/971/" title="海南" class="c1" target="_blank">海南</a>
请根据图表中提供的信息,解答下面的问题:
(1)
在调查活动中,教育局采取的调查方式是___________(填写“普查”或“抽样调查”);
(2)
教育局抽取的初中生有___________人,扇形统计图中m的值是___________
(3)
已知平均每天完成作业时长在“ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ”分钟的9名初中生中有5名男生和4名女生,若从这9名学生中随机抽取一名进行访谈,且每一名学生被抽到的可能性相同,则恰好抽到男生的概率是___________
(4)
若该市共有初中生10000名,则平均每天完成作业时长在“ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ”分钟的初中生约有___________人.

20.无人机在实际生活中应用广泛.如图8所示,小明利用无人机测量大楼的高度,无人机在空中P处,测得楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 楼顶D处的俯角为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,测得楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 楼顶A处的俯角为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .已知楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 和楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 之间的距离 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 100米,楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的高度为10米,从楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> A处测得楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> D处的仰角为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> (点ABCDP在同一平面内).
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(1)
填空: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ___________度, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ___________度;
(2)
求楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的高度(结果保留根号);
(3)
求此时无人机距离地面 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的高度.

21.如图1,矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,点P在边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 上,且不与点BC重合,直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的延长线交于点E
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(1)
当点P <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的中点时,求证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 沿直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 折叠得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 落在矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的内部,延长 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 交直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点F
证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,并求出在(1)条件下 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的值;
连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 周长的最小值;
如图2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点H,点G <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的中点,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 时,请判断 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的数量关系,并说明理由.

22.如图1,抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 经过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,并交x轴于另一点B,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 在第一象限的抛物线上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 交直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(1)
求该抛物线的函数表达式;
(2)
当点P的坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 时,求四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的面积;
(3)
Q在抛物线上,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的值最大且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 是直角三角形时,求点Q的横坐标;
(4)
如图2,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> x轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,点H在射线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 上,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,过 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的中点K <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 轴,交抛物线于点I,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 为边作出如图所示正方形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,当顶点M恰好落在y轴上时,请直接写出点G的坐标.

参考答案

1.B

【解析】
根据相反数的定义可得结果.
因为-2+2=0,所以-2的相反数是2
故选:B

2.B

【解析】
科学记数法的表示形式为a×10n的形式,其中1≤|a|10n为整数.确定n的值时,要看把原数变成a时,小数点移动了多少位,n的绝对值与小数点移动的位数相同.当原数绝对值≥10时,n是正整数;当原数的绝对值<1时,n是负整数.
解:1200000000=1.2×109
故选:B

3.A

【解析】
根据代数式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的值为6列方程计算即可.
代数式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的值为6
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
故选:A

4.C

【解析】
根据从正面看得到的图形是主视图,可得答案.
解:从正面看第一层是三个小正方形,第二层中间一个小正方形,
故选:C

5.D

【解析】
利用中位数和众数的定义求出中位数和众数即可.
解:一共有7名同学,从小到大排列,中位数是4.6;在这7个数据中4.8出现的次数最多,所以众数是4.8
故选∶D

6.B

【解析】
根据幂的乘方,底数不变指数相乘;合并同类项法则,同底数幂相乘,底数不变指数相加;同底数幂相除,底数不变指数相减,对各选项分析判断后利用排除法求解.
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,选项错误,不符合题意;
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,选项正确,符合题意;
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,选项错误,不符合题意;
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,选项错误,不符合题意.
故选:B

7.C

【解析】
先利用反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的图象经过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,求出k的值,再分别计算选项中各点的横纵坐标之积,然后根据反比例函数图象上点的坐标特征进行判断.
解:∵反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的图象经过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
k(﹣3)=﹣6
(﹣2×(﹣3)=6≠﹣6
(﹣3×(﹣2)=6≠﹣6
(﹣6)=﹣6
,6×1
6≠﹣6
则它一定还经过(1,﹣6),
故选:C

8.C

【解析】
按照解分式方程的步骤解答即可.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
2-
x-1=0
2-
x+1=0
-
x=-3
x=3
检验,当x=3时,x-1≠0,故x=3是原分式方程的解.
故答案选C

9.B

【解析】
根据等边三角形的性质可得∠A=60°,再由三角形外角的性质可得∠AEF=∠1-∠A=80°,从而得到∠BEF=100°,然后根据平行线的性质,即可求解.
解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 是等边三角形,
∴∠
A=60°
∵∠1=140°

∴∠
AEF=∠1-∠A=80°
∴∠
BEF=180°-∠AEF=100°
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
∴∠2=∠
BEF=100°
故选:B

10.A

【解析】
由作法得BD平分∠ABC,然后利用等腰三角形底角相等计算即可.
由作法得BD平分∠ABC
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
故选:A

11.D

【解析】
先过点C做出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 轴垂线段CE,根据相似三角形找出点C的坐标,再根据平移的性质计算出对应D点的坐标.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
如图过点C <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 轴垂线,垂足为点E
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> , <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
C是由点B向右平移6个单位,向上平移2个单位得到,
D同样是由点A向右平移6个单位,向上平移2个单位得到,
A坐标为(03)
D坐标为(65),选项D符合题意,
故答案选D

12.B

【解析】
CCMAB延长线于M,根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,由菱形的性质表示出BC=4xBM=3x,根据勾股定理列方程计算即可.
CCMAB延长线于M
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
E是边 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的中点
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
菱形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> CEAB
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> CMAB
四边形EFMC是矩形
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
BM=3x
RtBCM中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> (舍去)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
故选:B

13. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

【解析】
原式直接提取a即可.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

14.23

【解析】
先估算出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的大小,然后确定范围在其中的整数即可.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
即比 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 大且比 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 小的整数为23
故答案为:23

15.25

【解析】
连接OB,如图,利用切线的性质得∠ABO=90°,再利用互余得到∠AOB=50°,然后根据三角形外角性质和等腰三角形的性质计算∠C的度数.
解:连接OB,如图,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
AB与⊙O相切,切点为B
OBAB
∴∠
ABO=90°
∴∠
AOB=90°-∠A=90°-40°=50°
OB=OC
∴∠
OBC=∠C
∴∠
AOB=∠OBC+∠C=2∠C
∴∠
C= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> AOB=25°
故答案为:25

16.     60      <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

【解析】
由正方形的性质证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,即可得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,再由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,即可求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,表示出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的面积,解方程即可.
正方形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> HL
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的面积等于1
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> (舍去)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
故答案为:60 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

17.15;(2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

【解析】
1)分别按算术平方根的概念,负整指数幂运算法则,绝对值的意义计算即可求出答案;
2)分别解出这两个不等式的解集,然后再求出这两个解集的公共部分即可求出答案.
1)原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
2)解不等式①,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
解不等式②,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
不等式组的解集是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

18.每千克有机黑胡椒售价为50元,每千克有机白胡椒售价为60

【解析】
设每千克有机黑胡椒售价为x元,每千克有机白胡椒售价为y元,根据题意列出关于xy的二元一次方程组,解之即可得出结论;
解:设每千克有机黑胡椒售价为x元,每千克有机白胡椒售价为y元.
根据题意,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
答:每千克有机黑胡椒售价为50元,每千克有机白胡椒售价为60元.

19.(1)抽样调查;
(2)300
30
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(4)3000

【解析】
1)根据题目中的“随机抽取几所学校部分初中生进行调查”可以判定是抽样调查;
2)读图可得,A组有45人,占15%,即可求得总人数;用B组的人数除以总人数再乘100%即可得出答案;
3)根据概率公式计算即可;
4)由样本中平均每天完成作业时长在“ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ”分钟的初中生的比例乘以10000人即可;
1)根据题目中的“随机抽取几所学校部分初中生进行调查”可以判定是抽样调查;故答案为:抽样调查;
2)教育局抽取的初中生人数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> (人)B组人数为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> B组所占的百分比为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
3)∵9名初中生中有5名男生和4名女生,∴从这9名学生中随机抽取一名进行访谈,恰好抽到男生的概率是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
4)样本中平均每天完成作业时长在“ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ”分钟的初中生占比 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ∴该市共有初中生10000名,则平均每天完成作业时长在“ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ”分钟的初中生约有 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 人.

20.(1)7560
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(3)110


【解析】
1)根据平角的定义求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,过点A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点E,再利用三角形内角和求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
2)在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 求出DE的长度再根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 计算即可;
3)作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点G,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点F,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 即可.
1)过点A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点E <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
由题意得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
2)由题意得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 米, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ∴楼 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的高度为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 米.
3)作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点G,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点F <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> AAS).∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ∴无人机距离地面 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的高度为110米.

21.(1)见解析
(2)①
见解析; <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ;②12,;③ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,见解析

【解析】
1)根据矩形的性质得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,再结合P <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的中点证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
2)①设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中,表示出三角形的其他两边,再由勾股定理列方程计算即可;
当点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 恰好位于对角线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 上时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 最小,利用勾股定理计算即可;
过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点M,证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,再由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 即可得到 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
1)解:如图9-1,在矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∵点P <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的中点,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
2)①证明:如图9-2,在矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .由折叠可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .在矩形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∵点P <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的中点,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .由折叠可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中,由勾股定理得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .②解:如图9-3,由折叠可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .由两点之间线段最短可知,当点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 恰好位于对角线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 上时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 最小.连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .③解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的数量关系是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .理由是:如图9-4,由折叠可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,交 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点M,∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴点H <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中点.∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∵点G <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中点,点H <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 中点,∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> .∴ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>

22.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(3)
Q的横坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 1
(4)
G(-4 + <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 0)

【解析】
1)将AC两点坐标代入解析式求解即可;
2)如图,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,令 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,求得点B的坐标,再根据各点的坐标确定OCOB的长,然后再根据 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 求解即可;
3)如图,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 轴,交直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点F,可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,进一步说明当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 最大时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 最大.设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,根据线段的核查运算求得PF的最大值;设点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 是直角三角形,则点Q不能与点PA重合,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,再分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 三种情况解答即可.
(4)
GL//y轴,作RCGLL,作MTKIK,作HWIK于点W,则△GLC <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> CRH,△ITM≌△HWI.根据GLCCRH可表示出H点坐标,从而表示出点K坐标,进而表示出I坐标,根据MT= IW,构建方程求得n的值.
(1)
解:∵抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 经过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
该抛物线的函数表达式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(2)
解:如图,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,令 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
(3)
解:如图1所示,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 轴,交直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 于点F
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 是定值,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 最大时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 最大.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 取得最大值 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,此时 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
设点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 是直角三角形,则点Q不能与点PA重合,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,下面分三类情况讨论:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,如图2所示,
过点P <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的延长线于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,如图3所示,过点P作直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,过点Q <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,如图4所示,过点Q <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的延长线于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
综上所述,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 的值最大且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 是直角三角形时,点Q的横坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 1
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
1                                             2                                           3                                          4
(4)
如图,作GL//y轴,作RCGLL,作MTKIK,作HWIK于点W,则△GLCCRH,△ITM≌△HWI.
RH = OG= -n
CR= GL= OC= 3
MT= IW
G(n0)H(33+ n)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> +n+3+3)
TM=IM
∴ (n+3)2+ 2(n+3)- 12= 0
n1 = -4+ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>
n2 =-4- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> (舍去)
G(-4 + <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a> 0)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/971/" title="海南" class="c1" target="_blank">海南</a>