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【329642】3.3实数

时间:2025-02-02 18:28:08 作者: 字数:8783字



3.3实数同步检测

一、选择题

1.如图,若A是实数a在数轴上对应的点,则关于a-a1的大小关系表示正确的是(  )
 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

A. a1<-a                        B. a<-a1                        

C. 1<-aa                        D. aa1

2.下列说法中,不正确的是(   )

A. ﹣3.1  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 是负数             B. ﹣3.1  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 是有理数             

C. ﹣3.1  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 是无理数           D. ﹣3.1  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 是分数

3.实数abcd在数轴上的对应点的位置如图所示,这四个数中,绝对值最大的是(  )
 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

A. a                                           B. b                                       C. c                                           D. d

4.-5038这四个数中,最小的数是()

A. -5                                         B. 0                                        C. 3                                          D. 8

5.在实数-30 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>3中,最小的实数是(    )

A. 3          B. 0          C.  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>             D. 3

6.a的相反数是(  )

A. |a|                                        B.  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>                                        C. ﹣a                                        D.  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

7.通过估算,估计  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 的大小应在(   )

A. 78之间                      B. 8.08.5之间                      

C. 8.59.0之间                  D. 910之间

8.下列说法正确的是(       )

A. 非负数包括零和整数                       B. 正整数包括自然数和

C. 零是最小的整数                           D. 整数和分数统称为有理数

9.在期末复习课上,老师要求写出几个与实数有关的结论:小明同学写了以下5个:
任何无理数都是无限不循环小数;
有理数与数轴上的点一一对应;
13之间的无理数有且只有  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>4个;
 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>
是分数,它是有理数;
由四舍五入得到的近似数7.30表示大于或等于7.295,而小于7.305的数.
其中正确的个数是(   )

A. 1                                        B. 2                                       

C. 3                                        D. 4

10.化简|1- <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> |+1的结果是(  )

A. 2- <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> ​                                    B. 2+ <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

C.  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> ​                                     D. 2

二、填空题

11.﹣27的立方根与  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 的算术平方根的和________

12.比较大小: <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>  ________1.(填“>”、“=”或“<”)

13.比较大小:2  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> ________  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

14.已知(x﹣y+32+  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =0,则x+y=________

15.如图,以数轴的单位长度线段为边长作一个正方形,以表示数2的点为圆心,正方形对角线长为半径画半圆,交数轴于点A和点B,则点A表示的数是________ <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

16. <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 的小数部分为a,则a8+a= ________

17. <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> ​-2的相反数是 ________

18.在实数0 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> ,﹣3.140.1010010001…(每两个1之间的0的个数依次增加1),  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> ,无理数有________个,有理数有________个,负数有________个.

三、计算题

19.计算:  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>













20.如图,abc分别是数轴上ABC所对应的实数.试化简  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +|a﹣b|+  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +|b﹣c| <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>













21.计算:

1 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

2 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> )﹣  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>












22.计算题: ①已知mn,求  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 的值;
已知a0,求  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 的值.











23.计算:

1 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

2 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>


参考答案

一、选择题

1. A 2.C 3.A 4.A 5.A 6.C 7.C 8.D 9.B 10.C

二、填空题

11.0 12.13.14. 1 15.2﹣  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 16.1 17.2- <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> ​ 18.332

三、计算题

19.解:  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =2﹣3﹣1﹣(﹣2
=﹣1﹣1+2
=0

20.解:由数轴可得: a﹣b0c0b﹣c0a+b0
 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +|a﹣b|+  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +|b﹣c|
=c﹣a+b+a+b+b﹣c
=3b

21.1)解:原式=4+  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +3=9  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>
2)解:原式=5﹣1﹣0.5=3.5

22.解:①∵mn, ∴  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>
=n﹣m+n﹣m
=2n﹣2m

②∵a
0
 <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>
=﹣a+a
=0

23.1)解:  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =0.2+4﹣0.5
=3.7
2)解:  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>=  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> ×  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> ×  <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>
=3﹣2
=1