已知
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d893ad056c01ae816bd1678a1d24aed1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2b132fd70b2b00279a1f85a1949db8f.png)
更新时间:2022-10-20 16:22:49
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相似题推荐
解答题-计算题
|
适中
(0.65)
【推荐1】已知
.
(1)化简
;
(2)若
满足不等式组
且
为整数,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1e4018436c8c65dc9fc4c0999dc7ff7.png)
(1)化简
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4969e9363d14f5bb6916aa4343851da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐1】求代数式
的值,其中a=﹣2020
如图是小亮和小芳的解答过程.
小亮:解:原式=![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73bed492d11b8db204d86fe0cd4ed801.png)
小芳:解:原式=![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76e1d870dc6d86105aa2a292fe0619ff.png)
(1) 的解法是错误的;
(2)错误的原因在于未能正确地运用二次根式的性质: ;
(3)求代数式
的值,其中a=﹣2019.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33c38ac2bd5879ae57c2a64a1f0de90d.png)
如图是小亮和小芳的解答过程.
小亮:解:原式=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73bed492d11b8db204d86fe0cd4ed801.png)
小芳:解:原式=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76e1d870dc6d86105aa2a292fe0619ff.png)
(1) 的解法是错误的;
(2)错误的原因在于未能正确地运用二次根式的性质: ;
(3)求代数式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ba3ef2572c111df4a08580fa5e706a.png)
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解答题-计算题
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适中
(0.65)
【推荐2】阅读材料,解答下列问题:
例:当
时,如
,则
,故此时
的绝对值是它本身;当
时,
,故此时
的绝对值是0;当
时,如
,则
,故此时
的绝对值是它的相反数.综上所述,一个数的绝对值要分三种情况,即:
,这种分析方法渗透了数学中的分类讨论思想.
(1)请仿照例中的分类讨论,分析
的各种化简后的情况;
(2)猜想
与
的大小关系;
(3)已知实数
,在数轴上的位置如图所示,试化简:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6288cd97af33b160e66405fc48a3e095.png)
例:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab839d8569171afab5ed55c22013aa72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d21e9fffd1e68f806623140410c5b79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b4d795709b0abcf47bceec2250f2f9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78f40aaecfde1453d0a3422645ed69d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e10e1c43b86a8cd4360ca9b57232164.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a81e971f501d78f5560c0c3d42f0f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41c54af96768de4bf79b2a8e457a6bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8700048c560ed4155336e489cb97a613.png)
(1)请仿照例中的分类讨论,分析
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40c0f57ea6e7089fb7b417818f664b96.png)
(2)猜想
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40c0f57ea6e7089fb7b417818f664b96.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f8d40e257f9c446b8e30fa841b74bbd.png)
(3)已知实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7f5573b30734d65648f61c0a94c98de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6288cd97af33b160e66405fc48a3e095.png)
![](https://img.xkw.com/dksih/QBM/2020/9/25/2559994432282624/2579451062099968/STEM/4e9939e2573f4f17907dac6d531c721e.png?resizew=190)
您最近一年使用:0次
解答题-计算题
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适中
(0.65)
【推荐2】阅读下列材料,然后解答问题:
在进行二次根式的化简与计算时我们有时会遇到如:
,
这样的式子,其实我们还可以将其进一步化简:
;
.
以上将分母中的根号化去的过程,叫做分母有理化.
(1)根据上面规律化简:
=______;
=______.
(2)化简下列各式
①
,
②
,
③
,
④
.
(3)用含n(n≥1的整数)的式子写出(2)中第n个式子,并化简.
在进行二次根式的化简与计算时我们有时会遇到如:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04e075b45121e52ae84cb33fcf3c4114.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f6d7b69b454f0a51548dd8a3482174a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99fec77e7f10409365797add74abb02c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad8e7b3df103912abaac31bc41afa84f.png)
以上将分母中的根号化去的过程,叫做分母有理化.
(1)根据上面规律化简:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66ecaf9fe4eb0c06bf544187af8d51b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e3961bc00f7380ea4cd29c757fab41c.png)
(2)化简下列各式
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b56e54fa376cc3740ccd5501c789b0d.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07d9c9dbcf646c087d86a7d33a4cd17c.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/276041ac45d083a6fe888a076ce795cd.png)
④
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a9de8824e6ddda6e6b5e0546df02a64.png)
(3)用含n(n≥1的整数)的式子写出(2)中第n个式子,并化简.
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