举报
huifahuifa
好吧,刚刚得到了f(x)=f(x+4),这个应该可以看懂了吧?那么f(99)=f(99-4),这个应该可以看懂吧?f(x)=f(x+4) 那么f(x)=f(x-4),那么f(99)=f(99-4)=f(95)=f(95-4)=f(91)=f(91-4)=f(87)=f(87-4)=f(83)=f(83-4)=f(79)=f(79-4)=f(75)=f(75-4)=f(71)=f(71-4)=f(67)=f(67-4)=f(63)=f(63-4)=f(59)=f(59-4)=f(55)=f(55-4)=f(51)=f(51-4)=f(47)=f(47-4)=f(43)=f(43-4)=f(39)=f(39-4)=f(35)=f(35-4)=f(31)=f(31-4)=f(27)=f(27-4)=f(23)=f(23-4)=f(19)=f(19-4)=f(15)=f(15-4)=f(11)=f(11-4)=f(7)=f(7-4)=f(3)=1/f(1)=1/2.