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【329575】2.6 实数 同步练习1

时间:2025-02-02 18:24:42 作者: 字数:2174字


 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

2.6 实数

一、填空题

1.在实数中绝对值最小的数是________,在负整数中绝对值最小的数是________.

2.已知一个数的相反数小于它本身,那么这个数是________.

3.设实数a≠0,则a与它的倒数、相反数三个数的和等于____________,三个数的积等于_____________.

4.任何一个实数在数轴上都有一个__________与它对应,数轴上任何一个点都对应着一个___________.

5.绝对值等于它本身的数是________,平方后等于它本身的数是________.

6.实数a,b在数轴上所对应的点的位置如图所示,则2a__________0,a+b_________0,-|ba_______0,化简|2a|-|a+b=_______.

 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

7.已知: <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =102, <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =0.102,x=________.

8. <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> +2xy5=0,x=________,y=________.

二、选择题

1.下列说法中,正确的是( )

A.任何实数的平方都是正数 B.正数的倒数必小于这个正数

C.绝对值等于它本身的数必是非负数 D.零除以任何一个实数都等于零

2.a,b为实数,下列命题中正确的是( )

A.ab,a2b2 B.a>|b,a2b2

C.若|a|>b,a2b2 D.a0,ab,a2b2

3.全体小数所在的集合是( )

A.分数集合 B.有理数集合 C.实数集合 D.无理数集合

三、铁笔判官

甲、乙两人计算算式x+ <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> 的值,当x=3的时候,得到不同的答案,其中甲的解答是x+ <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =x+ <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =x+1x=1

乙的解答是x+ <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =x+ <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =x+x1=5

 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a>

哪一个答案是正确的?为什么?对的说出理由,错的指出错误的原因.





四、解决问题

1.请你试着计算下列各题

(2) <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =____ (3) <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =_____

(6)|π|=______ (7)|4π|=______

(9) <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =_____ (10) <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =_____

2.快速抢答

通过以上运算,在实数范围内,相反数、倒数、绝对值的意义和有理数是否一样?


请填空:

2 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =_____  <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =_____

 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =_____  <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =_____

参考答案

一、

1.0 1

2.正数

3. <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> a

4.点实数

5.0和正数 01

6.< > < -3ab

7.0.010404

8.x=2 y=1

二、

1.C 2.B 3.C

三、乙的结果对,∵x=3,∴1x0 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =x1

而不是 <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/50/" title="同步" class="c1" target="_blank">同步</a> <a href="/tags/842/" title="实数" class="c1" target="_blank">实数</a> =1x,∴乙对

四、略