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【327679】2022年黑龙江省牡丹江市中考数学真题

时间:2025-01-20 19:59:00 作者: 字数:24002字
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2022年黑龙江省牡丹江市中考数学真题

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一、选择题

1.在下列图形中,既是轴对称图形又是中心对称图形的是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

2.下列计算正确的是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

3.函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中,自变量x的取值范围是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

4.由若干个相同的小立方体搭成的几何体的三视图如图所示,则搭成这个几何体的小立方体的个数是(  )
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
A
3
B
4
C
5
D
6

5.不透明袋子中装有红、绿小球各一个,除颜色外无其他差别,随机摸出一个小球后,放回并摇匀,再随机摸出一个,两次都摸到红球的概率为(  )
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

6.如图,BD <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的直径,AC在圆上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的度数是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
A
50°
B
45°
C
40°
D
35°

7.如图,等边三角形OAB,点Bx轴正半轴上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,若反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 图象的一支经过点A,则k的值是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

8.若关于x的方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 无解,则m的值为(       
A
1
B
13
C
12
D
23

9.圆锥的底面圆半径是1,母线长是3,它的侧面展开图的圆心角是(       
A
90°
B
100°
C
120°
D
150°

10.观察下列数据: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,…,则第12个数是(       
A
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

11.下列图形是黄金矩形的折叠过程:第一步,如图(1),在一张矩形纸片一端折出一个正方形,然后把纸片展平;第二步,如图(2),把正方形折成两个相等的矩形再把纸片展平;第三步,折出内侧矩形的对角线AB,并把AB折到图(3)中所示的AD处;第四步,如图(4),展平纸片,折出矩形BCDE就是黄金矩形.则下列线段的比中:① <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,② <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,③ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,④ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,比值为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
A
.①②
B
.①③
C
.②④
D
.②③

12.如图,抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的对称轴是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,并与x轴交于AB两点,若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则下列结论中:① <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;② <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;③ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;④若m为任意实数,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,正确的个数是(       
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
A
1
B
2
C
3
D
4

评卷人

得分




二、填空题

13.2022313日北京冬残奥会闭幕当天,奥林匹克官方旗舰店再次发售1000000只“冰墩墩”,很快便售罄.数据1000000用科学记数法表示为______

14.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,请添加一个条件______,使 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

15.某商品的进价为每件10元,若按标价打八折售出后,每件可获利2元,则该商品的标价为每件______元.

16.一列数据:123x55的平均数是4,则这组数据的中位数是______

17. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的直径 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> AB <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的弦, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,垂足为M <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则AC的长为______

18.抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 向右平移2个单位长度,再向上平移3个单位长度,得到抛物线的顶点坐标是______

19.如图,在平面直角坐标系中,点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,将平行四边形OABC绕点O旋转90°后,点B的对应点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 坐标是______
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

20.如图,在等腰直角三角形ABC和等腰直角三角形ADE中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,点DBC边上,DEAC相交于点F <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,垂足是G,交BC于点H.下列结论中:① <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;② <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;③若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;④ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,正确的是______
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

评卷人

得分




三、解答题

21.先化简,再求值. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

22.已知抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> x轴交于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 两点,与y轴交于点C,顶点为D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(1)
求该抛物线的解析式;
(2)
连接BCCDBDPBD的中点,连接CP,则线段CP的长是______.注:抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的对称轴是直线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,顶点坐标是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

23.在菱形ABCD中,对角线ACBD的长分别是68,以AD为直角边向菱形外作等腰直角三角形ADE.连接CE.请用尺规或三角板作出图形,并直接写出线段CE的长.

24.为推进“冰雪进校园”活动,我市某初级中学开展:A.速度滑冰,B.冰尜,C.雪地足球,D.冰壶,E.冰球等五种冰雪体育活动,并在全校范围内随机抽取了若干名学生,对他们最喜爱的冰雪体育活动的人数进行统计(要求:每名被抽查的学生必选且只能选择一种),绘制了如图所示的条形统计图和扇形统计图.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
请解答下列问题:
(1)
这次被抽查的学生有多少人?
(2)
请补全条形统计图,并写出扇形统计图中B类活动扇形圆心角的度数是______
(3)
若该校共有1500人,请你估计全校最喜爱雪地足球的学生有多少人?

25.在一条平坦笔直的道路上依次有ABC三地,甲从B地骑电瓶车到C地,同时乙从B地骑摩托车到A地,到达A地后因故停留1分钟,然后立即掉头(掉头时间忽略不计)按原路原速前往C地,结果乙比甲早2分钟到达C地,两人均匀速运动,如图是两人距B地路程y(米)与时间x(分钟)之间的函数图象.
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
请解答下列问题:
(1)
填空:甲的速度为______/分钟,乙的速度为______/分钟;
(2)
求图象中线段FG所在直线表示的y(米)与时间x(分钟)之间的函数解析式,并写出自变量x的取值范围;
(3)
出发多少分钟后,甲乙两人之间的路程相距600米?请直接写出答案.

26.如图, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,点EF在直线BC上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> .如图①,易证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> .请解答下列问题:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(1)
如图②,如图③,请猜想BCBEBF之间的数量关系,并直接写出猜想结论;
(2)
请选择(1)中任意一种结论进行证明;
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ______ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ______

27.某工厂准备生产AB两种防疫用品,已知A种防疫用品每箱成本比B种防疫用品每箱成本多500元.经计算,用6000元生产A种防疫用品的箱数与用4500元生产B种防疫用品的箱数相等.请解答下列问题:
(1)
AB两种防疫用品每箱的成本;
(2)
该工厂计划用不超过90000元同时生产AB两种防疫用品共50箱,且B种防疫用品不超过25箱,该工厂有几种生产方案?
(3)
为扩大生产,厂家欲拿出与(2)中最低成本相同的费用全部用于购进甲和乙两种设备(两种都买).若甲种设备每台2500元,乙种设备每台3500元,则有几种购买方案?最多可购买甲,乙两种设备共多少台?(请直接写出答案即可)

28.如图,在平面直角坐标系中,四边形ABCDAy轴的正半轴上,BCx轴上,AD//BCBD平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,交AO于点E,交AC于点F <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> .若OBOC的长分别是一元二次方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的两个根,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
请解答下列问题:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(1)
求点BC的坐标;
(2)
若反比例函数 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 图象的一支经过点D,求这个反比例函数的解析式;
(3)
平面内是否存在点MNMN的上方),使以BDMN为顶点的四边形是边长比为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的矩形?若存在,请直接写出在第四象限内点N的坐标;若不存在,请说明理由.

参考答案

1.C

【解析】
根据轴对称图形和中心对称图形的定义判断即可.在平面内,如果一个图形沿一条直线折叠,直线两旁的部分能够完全重合,这样的图形叫做轴对称图形,在同一平面内,如果把一个图形绕某一点旋转180°,旋转后的图形能和原图形完全重合,那么这个图形就叫做中心对称图形.
解:A、是轴对称图形,不是中心对称图形,不符合题意;
B
、不是轴对称图形,是中心对称图形,不符合题意;
C
、是中心对称图形,也是轴对称图形,故符合题意;
D
、是轴对称图形,不是中心对称图形,不符合题意.
故选C

2.B

【解析】
根据合并同类项法则、同底数幂的乘除法、负整数指数幂、幂的乘方法则逐项判断即可得.
解:A <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则此项错误,不符题意;
B
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则此项正确,符合题意;
C
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则此项错误,不符题意;
D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则此项错误,不符题意;
故选:B

3.D

【解析】
根据二次根式的被开方数的非负性即可得.
解:由二次根式的被开方数的非负性得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:D

4.B

【解析】
从俯视图中可以看出最底层小正方体的个数及形状,从主视图可以看出每一层小正方体的层数和个数,从而算出总的个数.
解答:解:从主视图看第一列两个正方体,说明俯视图中的左边一列有两个正方体,主视图右边的一列只有一行,说明俯视图中的右边一行只有一列,所以此几何体共有四个正方体.故选B

5.D

【解析】
用列表法或树状图法可以列举出所有等可能出现的结果,然后看符合条件的占总数的几分之几即可.
解:两次摸球的所有的可能性树状图如下:

第一次   第二次


开始 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 两次都是红球 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选D

6.C

【解析】
BD是圆O的直径,可求得∠BCD = 90°又由圆周角定理可得∠D=∠A= 50°,继而求得答案.
解:∵BD <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的直径,
∴∠
BCD=90°
∴∠
D=∠A= 50°
∴∠
DBC= 90°-∠D = 40°
故选: C

7.D

【解析】
过点AACx轴于点C,则可根据勾股定理和三角形的面积求出OCOA的长度,即可得出点A的坐标,将点A坐标代入反比例函数表达式即可求出k
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
过点AACx轴于点C
三角形AOB为等边三角形,
∴∠
AOB=60°
设点Aab),
CO=aAO=AB=OB=2a,根据勾股定理可得∶AC=b= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,解得:a=2
b= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即点A(2  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> )
把点A(2  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> )代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 得,k= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:D

8.B

【解析】
先将分式方程化成整式方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,再分①整式方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 无解,②关于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 有增根两种情况,分别求解即可得.
解:将方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 化成整式方程为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
因为关于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 无解,
所以分以下两种情况:
整式方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 无解,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
关于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的方程 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 有增根,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
综上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值为13
故选:B

9.C

【解析】
圆锥的侧面展开图是一个扇形,利用弧长公式进行计算即可得.
解:设这个圆锥的侧面展开图的圆心角是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
由题意得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
则这个圆锥的侧面展开图的圆心角是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:C

10.D

【解析】
仔细观察给出的一列数字,从而可发现,分子等于其项数,分母为其所处的项数的平方加1,根据规律解题即可.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,…,根据规律可得第n个数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
12个数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故选:D

11.B

【解析】
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,分别求出比值,作出判断.
解:设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
由折叠可知, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
比值为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的是①③,
故选:B

12.C

【解析】
根据函数图像的开口方向,对称轴,图像与y轴的交点,即可判断①;根据对称轴x= - 2OA=5OB,可得OA=5OB1,点A(-50),点B10),当x1时,y0即可判断②;根据对称轴x= - 2以及a+b+c=0ac的关系,即可判断③;根据函数的最小值是当x=-2y4a2bc即可判断④.
解:①观察图像可知a0b0c0
abc0
故①错误
②∵
对称轴为直线x= - 2 OA5OB,可得OA=5 OB=1
A(-50),点B10
x-1时,y0abc= 0
ac2b2=(abc)(acb)=0
故②正确
抛物线的对称轴为直线x=- 2,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>        =-2
b4a
abc0
∴ 5
ac0
c=-5a
∴9a4c=-11a0
故③正确
x=-2时函数有最小值y4a2bc
am2bm2b≥4a,可得
am2bmc≥4a2bc
m为任意实数,则am2bm2b≥4a
故④正确
故选C

13. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
根据科学记数法的定义即可得.
解:科学记数法:将一个数表示成 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的形式,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 为整数,这种记数的方法叫做科学记数法,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (这里 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 省略不写),
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

14.A=∠D(答案不唯一)

【解析】
根据角边角可证得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即可.
解:可添加∠A=∠D,理由如下:
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
∴∠
DCE=∠ACB
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,∠A=∠D
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为:∠A=∠D(答案不唯一)

15.15

【解析】
设该商品的标价为每件x元,根据八折出售可获利2元,可得出方程:80%x-10=2,再解答即可.
解:设该商品的标价为每件x元,
由题意得:80%x-10=2
解得:x=15
所以该商品的标价为每件15元.
故答案为:15

16.4

【解析】
先根据平均数的公式求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的值,再根据中位数的定义即可得.
解:由题意得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
将这组数据按从小到大进行排序为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则第3个数和第4个数的平均数即为中位数,
所以这组数据的中位数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为:4

17. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
分①点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 上,②点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 上两种情况,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,先利用勾股定理求出 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的长,再在 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中,利用勾股定理求解即可得.
解:由题意,分以下两种情况:
如图,当点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 上时,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的直径 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
如图,当点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 在线段 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 上时,连接 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
同理可得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
综上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的长为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

18.35

【解析】
先求出抛物线的顶点坐标,再根据向右平移横坐标加,向上平移纵坐标加求出平移后的抛物线的顶点坐标即可.
解:抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的顶点坐标为(12),
将抛物线y=x-12+2再向右平移2个单位长度,向上平移3个单位长度,
平移后的抛物线的顶点坐标为(35).
故答案为:(35).

19. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
根据旋转可得: BM = B1M1 = B2M2 = 3,∠AOA1 =∠AOA2 = 90°,可得B1B2的坐标,即是B'的坐标.
解:∵A(-12)OC= 4
C(40)B(32)M(02)BM = 3
AB//x轴,BM= 3
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
将平行四边形OABC绕点O分别顺时针、逆时针旋转90°后,
由旋转得:OM=OM1=OM2=2
AOA1=∠AOA2=90°
BM=B1M1=B2M2=3
A1B1x轴,A2B2x轴,
B1B2的坐标分别为: (-23)(2-3)
B'即是图中的B1B2,坐标就是, B' (-23)(2-3)
故答案为: (-23)(2-3)

20.②③##③②

【解析】
先证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 再证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 与题干信息不符,可判断①不符合题意;再证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 可判断②符合题意;如图,连接EH,求解 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 再建立方程组 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 可判断③符合题意;证明 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 与题干信息不符,可判断④不符合题意;从而可得答案.
解:∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
等腰直角三角形ABC和等腰直角三角形ADE
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 平分 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 与题干信息不符,故①不符合题意;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,故②符合题意;
如图,连接EH
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> BD=3,故③符合题意;
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 与题干信息不符,故④不符合题意;
故答案为:②③

21.x-1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
原式括号中两项通分并利用同分母分式的减法法则计算,同时利用除法法则变形,约分得到最简结果,把x的值代入计算即可求出值.
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时,
原式 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

22.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
1)根据点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的坐标,利用待定系数法即可得;
2)先根据抛物线的解析式求出点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的坐标,再利用中点坐标公式可得点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的坐标,然后利用两点之间的距离公式即可得.
(1)
解:将点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 代入 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
则该抛物线的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(2)
解:抛物线 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的顶点坐标为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 的中点,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
故答案为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

23.作图见解析; <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 两种情况,利用三角形全等及菱形的性质,求出相应线段长度,再利用勾股定理即可求解.
解:(1)如下图所示,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
作图方法:利用三角板以AD为直角边,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,取 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> CA的延长线于点F
在菱形ABCD中,对角线ACBD的长分别是68
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
又∵  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
2)如下图所示,当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
作图方法:利用三角板以AD为直角边,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,取 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> BD的延长线于点F,作 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> EF的延长线于点G
同(1)可证 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
综上, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

24.(1)这次被抽查的学生有60
(2)
补图见解析,120°
(3)200


【解析】
1)结合条形统计图和扇形统计图可知,被抽查的学生人数=A类人数÷A类百分比
2)用抽查的总人数减去其他项目的人数即可得到D类人数,B类活动圆心角度数=360°×B类所占的百分比.
3)用全校人数乘以热爱雪地足球的学生所占百分比即可求出全校最喜爱雪地足球的学生有多少人.
(1)
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (人).
答:这次被抽查的学生有60人.
(2)
解:60-(12+20+8+4)=16()
补全图形见图,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
360°×
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> =120°B类活动扇形圆心角的度数是120°
(3)
解: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (人).
答:全校最喜爱雪地足球的学生有200人.

25.(1)300800
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(3)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 分钟, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 分钟,6分钟

【解析】
1)根据函数图象先求出乙的速度,然后分别求出乙到达C地的时间和甲到达C地的时间,进而可求甲的速度;
2)利用待定系数法求出函数解析式,根据题意可得自变量x的取值范围;
3)设出发t分钟后,甲乙两人之间的路程相距600米,分两种情况:①乙从B地到A地时,两人相距600米,②乙从A地前往C时,两人相距600米, 分别列方程求解即可.
(1)
解:由题意可得:乙的速度为:(800+800÷31)=800/分钟,
乙到达C地的时间为:32400÷8006分钟,
甲到达C地的时间为:628分钟,
甲的速度为:2400÷8300/分钟,
故答案为:300800
(2)
解:由(1)可知G62 400),
设直线FG的解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> F30),G62 400)两点,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
直线FG的解析式为: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
自变量x的取值范围是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(3)
解:设出发t分钟后,甲乙两人之间的路程相距600米,
乙从B地到A地时,两人相距600米,
由题意得:300t800t600
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
乙从A地前往C时,两人相距600米,
由题意得:300t800t3)=600800t3)-300t600
解得: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 6
答:出发 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 分钟或 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 分钟或6分钟后,甲乙两人之间的路程相距600米.

26.(1)图②: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ;图③: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(2)
证明见解析
(3)8
1418

【解析】
1)先判断两个三角形全等,再结合线段的和差求解即可;
2)先证两个三角形全等,再结合线段的和差求解即可;
3)过点A作△ABC的高AG,求出AG的长,再根据三角形的面积求出BC的长,进而求出BF即可.
(1)
解:图②: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
图③: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(2)
解:图②中
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
BC=FE
BF=BC+CE+EF=BC+CE+BC
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
或图③中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
BC=FE
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(3)
解:过点AAGBCG
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
∴∠
B=∠F=60°
Rt△ABG中,
AB=6,∠B =60°
AG=AB·sin B=6×sin 60°= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
BC=8
又∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
BF=BC+BE=8+8-2=14,或BF=BC+BE=8+8+2=18
故答案为:81418
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

27.(1)A种防疫用品2000/箱,B种防疫用品1500/
(2)
共有6种方案
(3)4
种,33

【解析】
1)设B种防疫用品成本x/箱,A种防疫用品成本 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> /箱,根据题意列出分式方程解得即可;
2)设B种防疫用品生产m箱,A种防疫用品生产 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 箱,根据题意列得不等式解得即可;
3)先根据(2)求得最低成本,设购进甲和乙两种设备分别为ab台,根据题意列得方程,解得正整数解即可.
(1)
解:设B种防疫用品成本x/箱,A种防疫用品成本 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> /箱,
由题意,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得x1 500
检验:当x1 500时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,所以x1500是原分式方程的解,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (元/箱),
答:A种防疫用品2000/箱,B种防疫用品1500/箱;
(2)
解:设B种防疫用品生产m箱,A种防疫用品生产 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 箱,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
B种防疫用品不超过25箱,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
m为正整数,
m202122232425,共有6种方案;
(3)
解:设生产AB两种防疫用品费用为w
w=1500m+200050-m=-500m+100000
k0
wm的增大而减小,
m=25时,w取得最小值,此时w=87500
设购进甲和乙两种设备分别为ab台,
∴2500
a+3500b=87500
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
两种设备都买,
ab都为正整数,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
一共4种方案,最多可购买甲乙两种设备共28+5=33台.

28.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> C20
(2)
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(3)
存在,N1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ),N2-912),N3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>

【解析】
1)解方程得出方程的解,即可确定点BC的坐标;
2)首先证明∠AFB=∠AOB90°,再证明AB=BC=5,由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,从而得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,即可得到AD=AD=5,再由勾股定理求出AO=4,得出点D的坐标即可求出反比例函数解析式;
3)如图,分两种情况讨论求解即可.
(1)
解:由 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
OBOC的长分别是方程的两个根,且OBOC
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> C20).
(2)
解:∵AOBC
∴∠
AOB90°
∵∠
CAO=∠DBC <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
∴∠
AFB=∠AOB90°
BD平分∠ABC
∴∠
ABD=∠DBC
∵∠
AFB90°
∴∠
BAC=∠BCA
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
RtABO中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
D54).
反比例函数解析式为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
(3)
解:如下图,过点DDQx轴于点Q,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 轴于点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
四边形 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 是矩形,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ),
同理可求出N2-912),N3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
如图,过点DDEx轴于点E,过点 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> WT  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 于点F,设 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> x轴交于点G
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
BD是圆的直径,
E在圆上,
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
DE=4BE=3+5=8
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
由勾股定理得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ,解得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
GE=x,则BG=8-x,代入比例式得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
Rt <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> 中, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
解得, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> (舍去)
BG= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
由勾股定理可得,BF= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
同理可得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>
综上,点N的坐标为:N1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ),N2-912),N3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a> ), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/973/" title="黑龙江省" class="c1" target="_blank">黑龙江省</a> <a href="/tags/979/" title="牡丹江" class="c1" target="_blank">牡丹江</a> <a href="/tags/1102/" title="黑龙江" class="c1" target="_blank">黑龙江</a>