定义:我们将
与
称为一对“对偶式”.
因为
,可以有效的去掉根号,所以有一些题可以通过构造“对偶式”来解决.
例如:
,所以
与
互为“对偶式”.
(1)
的“对偶式”是________,
的“对偶式”是________.
(2)已知
,其中
.
①
的“对偶式”的值是________.
②利用“对偶式”的相关知识,求方程
中x的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9928ba39cdd5878aced506d3dbb9fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b87033f1efe85e559a9a3efc985be9d.png)
因为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50036f42d68bcb48ee54bf6a8e76856f.png)
例如:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9716b80c5256540830bd48ad968f5d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e833d2c9f895f404a733a7d389e3b07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acba2d76c389f6f53cc8cf757760cd02.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77abd3f77c42e53acb598fbc64cc22f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63319272787a2c3137212e4d11b0e887.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95c3a00640f05c28e85b3d2e2ba562f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44d16f50c58699f352885df1f7bc9132.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63319272787a2c3137212e4d11b0e887.png)
②利用“对偶式”的相关知识,求方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95c3a00640f05c28e85b3d2e2ba562f9.png)
23-24八年级下·江苏盐城·期中 查看更多[2]
更新时间:2024-05-28 17:45:18
|
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解答题-计算题
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适中
(0.65)
【推荐1】(1)已知
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;②
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(2)若
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(2)若
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您最近一年使用:0次
解答题-计算题
|
适中
(0.65)
【推荐1】(1)计算:
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(2)计算:
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(3)解方程:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/415d1ffc0af5234dba8f0737a67848d6.png)
(4)解方程:
(用配方法解)
(5)解方程:
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e0b5b2761c96a7c9ee5d75d915b380b.png)
(2)计算:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e33a662afd7539ffb386428a17338283.png)
(3)解方程:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/415d1ffc0af5234dba8f0737a67848d6.png)
(4)解方程:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9c54e675a515caa57b04d744dcc1395.png)
(5)解方程:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c1abcae77dff82fa0e5bd382c737e8.png)
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】计算:
(1)
;
(2)
;
(3)如果规定“⊙”为一种新的运算:
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,仿照例子计算,当
时,
的值.
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acf3f0cbfccaa589fc98091f32617815.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fae92718e56b4c6b0fdefda4f1fae72.png)
(3)如果规定“⊙”为一种新的运算:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34c26a9ae0988934c7816bfcc21016f2.png)
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您最近一年使用:0次