Question

已知y＝f (x)在定義域(-∞,0)內存在反函數,且f (x-1)＝x²-2x,則f^--1(-)等于

A.-               B.                  C.-                 D.

Answer 1

A 

解析：∵f (x-1)=x²-2x=(x-1)²-1，

∴f(x)=x²-1.∴x²-1=-,且x＜0.∴ x=-.