Question

函数y=lnx+1(x＞0)的反函数为(    )

A.y=e^x+1(x∈R)                    B.y=e^x-1(x∈R)

C.y=e^x+1(x＞1)                     D.y=e^x-1(x＞1)

Answer 1

解析：∵x＞0,∴lnx+1∈R，由y=lnx+1,得lnx=y-1,∴x=e^y-1.

∴y=e^x-1.

∴y=lnx+1(x＞0)的反函数为y=e^x-1(x∈R).

答案：B