题目

题型：不详难度：来源：

(本小题满分13分)
已知，函数．
（1）求函数的最小正周期；
（2）求函数的单调减区间；
（3）当时，求函数的值域．

答案

解：
··················································· 2分

································································· 5分
·············································································· 6分
······················································································· 7分
(1) 的最小正周期···································································· 8分
(2) 由得
∴的单调减区间为··············································· 10分
(3)

∵
∴    
∴
∴
即的值域为··············································································· 12分

解析

略