设函数f(x)=x/(x+1),则当x≠-1时,f[f(x)]=()

题目类型: 单选题

题目内容

设函数f(x)=x/(x+1),则当x≠-1时,f[f(x)]=()

题目选项

A. x/(x+1)
B. 1/(x+1)
C. x/(2x+1)
D. (2x+1)/x

正确答案

C

题目解析

复合函数的求法.由f(x)=x/(x+1),则f[f(x)]=f[x/(x+1)]=[x/(x+1)]/[x/(x+1)+1]=x/(2x+1),故选C.

题目纠错