Question

设f(x)=x-1/x+1,则f(x)+f(1/x)=?别人问的过程我都看了,很纠结啊,步骤怎么算都不对 .急.

Answer 1

1.因为 f(1/x)=(1/x-1)/(1/x+1)=(1-x)/(1+x)=-(x-1)/(x+1)=-f(x),

所以 f(x)+f(1/x)=0

2.(1/x-1)/(1/x+1)=(1/x-1)/(x+1/1)=(x+1)/(x-1)