【题文】已知函数 且),则的值域是 ( )A.B.C.
【题文】已知函数 且),则的值域是 ( )A.B.C.
题型:难度:来源:
答案
【答案】D
解析
【解析】
试题分析:由已知得函数
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182021-78078.png)
的定义域为
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182021-90887.png)
,则
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182022-71294.png)
,
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182022-28701.png)
,
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182022-56316.png)
,
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182022-41358.png)
,所以函数的值域为
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182022-69366.png)
.故正确答案为D
考点:函数的定义
举一反三
【题文】若函数
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182008-39023.png)
满足
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182008-91505.png)
,对定义域内的任意
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182009-71034.png)
恒成立,则称
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182008-39023.png)
为m函数,现给出下列函数:
①
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182009-39675.png)
; ②
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182009-52561.png)
; ③
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182010-62682.png)
; ④
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182010-49681.png)
其中为m函数的序号是
.(把你认为所有正确的序号都填上)
【题文】函数f(x)=
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182004-14771.png)
+
![](http://img.shitiku.com.cn/uploads/allimg/20200324/20200324182005-35272.png)
的定义域是( )
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