【题文】已知:.(1)若求的值;(2)若求的值.
【题文】已知:.(1)若求的值;(2)若求的值.
题型:难度:来源:
答案
解析
【解析】(1)
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234220-75248.gif)
……………………………2分
若
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234219-96613.gif)
则
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234220-29974.gif)
,解得:
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234219-31377.gif)
……………………………5分
(2)若
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234219-59334.gif)
则
①若
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234220-33354.gif)
为空集,则
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234220-59880.gif)
则
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234220-69932.gif)
; ………………………………………………8分
若
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234220-33354.gif)
为单元集,则
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234221-81604.gif)
解得:
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234221-42175.gif)
,将
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234221-42175.gif)
代入方程
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234221-73105.gif)
得:
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234221-97579.gif)
得:
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234222-29655.gif)
即
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234222-65810.gif)
符合要求;………………………………11分
若
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234220-29974.gif)
,则
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234219-31377.gif)
………………………………13分
综上所述,
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234219-86947.gif)
或
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234219-31377.gif)
. ………………………14分
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234127-31960.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234127-36314.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234127-83816.gif)
(1)求: A∪B,C
R(A∩B);
(2)若集合
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234127-76652.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234127-21937.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234127-24168.gif)
,满足
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234127-72836.gif)
,求实数
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234128-40542.gif)
的取值范围
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234101-46235.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234101-61160.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234101-17671.gif)
(1)求: A∪B,C
R(A∩B);
(2)若集合
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234102-40570.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234102-65000.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234102-94749.gif)
,满足
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234102-74152.gif)
,求实数
![](http://img.shitiku.com.cn/uploads/allimg/20200323/20200323234103-43029.gif)
的取值范围
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