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【323196】(安徽专版)2024春七年级数学下册 第6章 实数综合素质评价(新版)沪科版

时间:2025-01-15 19:18:11 作者: 字数:8205字
简介:

6章综合素质评价

一、选择题(本大题共10小题,每小题4分,满分40)

每小题都给出ABCD四个选项,其中只有一个是符合题目要求的.

1.2023·合肥45中校考】在实数, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>π0.808 008 000 8…(每两个8之间依次多10)中,无理数的个数是(  )

A.2 B.3

C.4 D.5

2.【易错题】在下列各式中,正确的是(  )

A. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> =-3 B. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> =-3

C. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> ±5 D. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> ±5

3.【母题:教材P20复习题T2(2) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 的算术平方根是(  )

A.8 B.±8

C.± <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> D. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

4.m <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> ,则实数m所在的范围是(  )

A.m<-5 B.4m5

C.4m<-3 D.m>-3

5.已知0x1,则在实数x <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>x2中最大的是(  )

A.x B. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

C. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> D.x2

6.一个正数x的平方根是2a35a,则a的值为(  )

A.2 B.2

C.3 D.3

7.已知a为实数,则下列四个数中一定为非负数的是(  )

A.a B. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

C. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> D. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

8.实数-π,-3,- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 的大小关系是(  )

A.3<-π<- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> B.π<-3<- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

C. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <-π<-3 D.3<- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <-π

9 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .2023·兰州改编】如图,将面积为7的正方形OABC和面积为9的正方形ODEF分别绕原点O顺时针旋转,使OAOD落在数轴上,点AD在数轴上对应的数分别为ab,则ba的值为(  )

A. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> B.3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

C. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 3 D.3

10. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 下面是一个按某种规律排列的数表,则第7行的第2个数是(  )

1

1

2

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>   <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  2

3

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>   <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>   <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  3

4

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>   <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>   <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>   <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>   <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  4

A. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> B. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

C. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> D.2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

二、填空题(本大题共4小题,每小题5分,满分20)

11.x    时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>1有最小值,这个最小值为    .

12.2023·内江】若ab互为相反数,c8的立方根,则2a2bc    .

13.已知半径为R的球体的体积是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> πR3,现要生产一种容积为36π dm3的球形容器,则这种容器的半径是    dm.

14.如果一个正方形ABCD的面积为69.

(1)正方形ABCD的边长a    .

(2)正方形ABCD的边长满足manmn表示两个连续的正整数,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 的值是    .

三、(本大题共2小题,每小题8分,满分16)

15.求下列各式中x的值.

(1)(3x2)216. (2) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> (2x1)3=-4.



16.计算:(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> (2)12 024 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .



四、(本大题共2小题,每小题8分,满分16)

17. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 某游乐场有如图所示的两个正方体木块摞在一起组成的座椅(大正方体放在地面上),现计划用彩色油漆喷绘,已知大正方体的体积为1 331 cm3,小正方体中被喷到彩色油漆的面积为125 cm2,求这个座椅的最高点A距离地面的高度AC的长.

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>



18.2023·黄山徽州区期中】已知x1的平方根是±23xy1的平方根是±4,求3x5y的平方根.



五、(本大题共2小题,每小题10分,满分20)

19.2023·合肥蜀山区月考】实践与探究:

(1)计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>     <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>     <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>    

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>      <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>    .

(2)根据(1)中的计算结果,回答:

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 一定等于a吗?你发现其中的规律了吗?请用自己的语言描述出来.

利用你总结的规律化简:若x2,则 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>    .

20. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 自由下落的物体的下落高度h(m)与下落时间t(s)的关系为h4.9 t2.有一名学生不慎让一个玻璃杯从19.6 m高的楼上自由下落,刚好另一名学生站在下落的玻璃杯正下方的地面上,在玻璃杯下落的同时楼上的学生惊叫一声,这时楼下的学生能躲开吗?(声音的传播速度为340 m /s)

六、(本题满分12)

21.如图,数轴上点A表示的数为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>1,将点A沿数轴向左平移3个单位长度到达点B,点B表示的数为m.

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

(1)m的值.

(2)化简: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> m)2.



七、(本题满分12)

22. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 观察下列各式及验证过程:

式①: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

验证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

式②: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

验证: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

(1)根据上述式①,式②的规律,请再写出一个按以上规律变化的式子.

(2)请写出满足上述规律的用n(n为自然数,且n≥2)表示的等式,并加以验证.



八、(本题满分14)

23.如图,数轴上AB两点对应的实数分别为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 10 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 17,点P从点A出发,以每秒1个单位长度的速度沿数轴正方向运动,同时点Q从原点O出发,以每秒2个单位长度的速度沿数轴正方向运动,设运动时间为t.

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

(1)0t2时,用含t的式子填空:AP    BQ    .

(2)t2时,求PQ的值.

(3)PQAB时,求t的值.(注: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 10 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 102 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 10)




答案

一、1.B

2.A【点拨】A. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> =-3,故此选项正确;

B. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 3,故此选项错误;

C. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 5,故此选项错误;

D. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 5,故此选项错误.故选A.

3.D

4.B【点拨】因为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>2.24,所以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>1.6,则m≈31.64.8,即4m5.故选B.

5.B

6.A【点拨】由题可知2a35a0,解得a=-2.故选A.

7.C【点拨】选项A中的a可以表示任何实数;选项B中的 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 的符号与a相同,所以也可以表示任何实数;选项C中的 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 表示-a的绝对值,根据绝对值的意义,可知 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 为非负数;选项D中的- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 表示 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 的相反数,由于 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 为非负数,所以- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 为非正数.故选C.

8.B

9.B【点拨】因为正方形OABC的面积为7,正方形ODEF的面积为9,所以OA  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>OD <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>3,即a <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>b3,所以ba3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

10.B【点拨】第2行的第2个数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

3行的第2个数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

4行的第2个数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> ,……,

所以第n行的第2个数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

所以第7行的第2个数是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

二、11.11 【点拨】因为当 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>1有最小值时,x10,即x=-1,所以当x=-1时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>1有最小值,最小值为1.

12.2

13.3

14.(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  (2)1

【点拨】(1)因为正方形ABCD的面积为69,所以正方形ABCD的边长a <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .(2)因为646981,所以8 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>9,即8a9.因为manmn表示两个连续的正整数,所以m8n9,所以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>23=-1.

三、15.【解】(1)开方,得3x243x2=-4,解得x <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>x=-2.

(2)方程两边同时乘以2,得(2x1)3=-8.

开立方,得2x1=-2

解得x=- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

16.【解】(1)原式=-6 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>3

=- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

(2)原式=-1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>132

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>3.

四、17.【解】由题知,小正方体中被喷到彩色油漆的有5个面,

所以每个面的面积为125÷525(cm2)

所以小正方体的棱长AB5cm.

因为大正方体的体积为1 331cm3

所以大正方体的棱长BC11cm

所以ACABBC51116(cm).

18.【解】由x1的平方根是±23xy1的平方根是±4,得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 解得 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

所以3x5y151025.

因为25的平方根为±5

所以3x5y的平方根为±5.

五、19.【解】(1)30.56 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>0

(2) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 不一定等于a.

a0时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> =-a

a≥0时, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>a,故 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 不一定等于a.

从中可以得到如下规律:正数和零的平方的算术平方根为其本身,负数的平方的算术平方根为其相反数.

2x

20.【解】能躲开.

因为玻璃杯下落的时间t <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>2(s),而声音传到楼下只需要19.6÷340≈0.06(s)2s.

所以楼下的学生能躲开.

六、21.【解】(1)m <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>13 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>2.

(2)因为m1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>21 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>10

所以|m1|= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>1.

因为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>m <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> 2)2

所以原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>122 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>3.

七、22.【解】(1)4× <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> (答案不唯一).

(2)n· <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> (n为自然数,且n≥2).

验证:n· <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

八、23.【解】(1)t <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>2t.

(2)t2时,点P对应的实数为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>2,点Q对应的实数为2×24,所以PQ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>24 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>2.

(3)因为t秒时,点P对应的实数为 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>t,点Q对应的实数为2t

所以PQ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .

因为PQAB

所以 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

解得t2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>t <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>

t的值是2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/843/" title="安徽" class="c1" target="_blank">安徽</a> .