Question

函数y=2^x+3(x∈R)的反函数为

A.y=log₂(x＞3)                      B.y=log₂(3-x)(x＞3)

C.y=log₂(x-3)(x＞3)                       D.y=log₂(x＞3)

Answer 1

解析：由y=2^x+3,得2^x=y-3,x=log₂(y-3),

∴y=2^x+3的反函数为y=log₂(x-3)(x＞3).

答案：C