【题文】若函数在上是增函数,则实数的取值范围是
【题文】若函数在上是增函数,则实数的取值范围是
题型:难度:来源:
答案
【答案】
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092345-14176.png)
解析
【解析】当
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092345-82130.png)
时,函数
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092346-20247.png)
,满足在
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092346-24664.png)
上单调递增。
当
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092346-24659.png)
时,若
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092346-52805.png)
在
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092346-24664.png)
上单调递增,则
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092347-57831.png)
即
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092347-53799.png)
。
综上所述,
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092347-57113.png)
。
举一反三
【题文】已知函数
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092328-84698.png)
,则函数
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092329-48475.png)
的值为________
【题文】已知函数
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092253-81968.png)
,
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092253-94086.png)
(
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092254-14265.png)
),若
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092255-30119.png)
,
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092255-35644.png)
,使得
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092255-73263.png)
,则实数
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092256-23819.png)
的取值范围是 ( )
【题文】
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092216-84014.png)
的单调增区间是
。
【题文】已知函数
![](http://img.shitiku.com.cn/uploads/allimg/20200327/20200327092207-59571.png)
是偶函数,则( )
A. k = 0 | B.k = 1 | C. k =4 | D.k∈Z |
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