Question

设f(x)=x分之x-1,则f(f(x))=

知道的说一下！急急急！感谢

Answer 1

f(x) = (x-1)/x,
f[f(x)] = f[(x-1)/x] = {[(x-1)/x]-1}/[(x-1)/x] = -1/(x-1)
选 B

Answer 2

如图

如图

追答

求采纳

Answer 3

应该选b吧。