2011·江苏南京·一模
名校
1 . 对于函数
,
,如果
是一个三角形的三边长,那么
也是一个三角形的三边长, 则称函数
为“保三角形函数”.
对于函数
,
,如果
是任意的非负实数,都有
是一个三角形的三边长,则称函数
为“恒三角形函数”.
(1)判断三个函数“
,
,
(定义域均为
)”中,哪些是“保三角形函数”?请说明理由;
(2)若函数
,
是“恒三角形函数”,试求实数
的取值范围;
(3)如果函数
是定义在
上的周期函数,且值域也为
,试证明:
既不是“恒三角形函数”,也不是“保三角形函数”.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66692ec49a458f9e48c7315d03dfc37b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/699d32dbd2b31b313ae7154c9a072775.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
对于函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1938c093dd2fbcb752d0eb7a18d143b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac4cbc7b067862a3d9c6789b392fc068.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f56f06476e9561c98011c8b85d3b2c24.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
(1)判断三个函数“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38e00b49aa78de649f34d8bb9d5179ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dac9ccfe180d478d9f3c00a8eac618c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4258a513f02771aaa29037be197928b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66692ec49a458f9e48c7315d03dfc37b.png)
(2)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45d79fd8146283ba9554e12a858499cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac4cbc7b067862a3d9c6789b392fc068.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(3)如果函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a813b5adbf5c7082561237894ba6d599.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d562dc22dfb3b81d0c3f88b54d063c2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d562dc22dfb3b81d0c3f88b54d063c2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a813b5adbf5c7082561237894ba6d599.png)
您最近一年使用:0次
11-12高一上·江苏淮安·期中
解题方法
2 . 已知函数
.
(Ⅰ)当
时,利用函数单调性的定义证明
在区间
上是单调减函数;
(Ⅱ)若函数
在区间
上是单调增函数,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76024312b2ad17fda4aefdef64dfb794.png)
(Ⅰ)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48adb8a59b5c02fad5eada1b35171cf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870ebc2f7aabb028024894568d749934.png)
(Ⅱ)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870ebc2f7aabb028024894568d749934.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次