Question

函数f(x)对于任意实数x满足条件f(x+2)=,若f(1)=-5,则f(f(5))=_________.

Answer 1

思路解析：由f(x+2)=,得f(x+4)= =f(x).

所以f(5)=f(1)=-5.

则f(f(5))=f(-5)=f(-1)=.

答案：-