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【330728】二次根式 同步练习2

时间:2025-02-11 18:40:01 作者: 字数:1200字

二次根式习题

一、选择题

1 <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/896/" title="根式" class="c1" target="_blank">根式</a> 的值是( ).

A0 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/896/" title="根式" class="c1" target="_blank">根式</a> C4 <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/896/" title="根式" class="c1" target="_blank">根式</a> D.以上都不对

2a≥0时, <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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</a> ,比较它们的结果,下面四个选项中正确的是( ).

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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</a>

C <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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</a> D- <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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</a>

二、填空题

1- <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/896/" title="根式" class="c1" target="_blank">根式</a> =________

2.若 <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/896/" title="根式" class="c1" target="_blank">根式</a> 是一个正整数,则正整数m的最小值是________

三、综合提高题

1.先化简再求值:当a=9时,求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/896/" title="根式" class="c1" target="_blank">根式</a> 的值,甲乙两人的解答如下:

甲的解答为:原式=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/896/" title="根式" class="c1" target="_blank">根式</a> =a+1-a=1

乙的解答为:原式=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/896/" title="根式" class="c1" target="_blank">根式</a> =a+a-1=2a-1=17

两种解答中,_______的解答是错误的,错误的原因是__________

2.若│1995-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/896/" title="根式" class="c1" target="_blank">根式</a> =a,求a-19952的值.

(提示:先由a-2000≥0,判断1995-a的值是正数还是负数,去掉绝对值)

3. -3≤x≤2时,试化简│x-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/896/" title="根式" class="c1" target="_blank">根式</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/896/" title="根式" class="c1" target="_blank">根式</a>


答案:

一、1C 2A

二、1-002 25

三、1.甲 甲没有先判定1-a是正数还是负数

2.由已知得a-2000≥0a≥2000

所以a-1995+ <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/896/" title="根式" class="c1" target="_blank">根式</a> =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/896/" title="根式" class="c1" target="_blank">根式</a> =1995a-2000=19952

所以a-19952=2000

3. 10-x