已知函数f(x)=2^(x+1),则f^-1 (4)等于?_数学解答

已知函数f(x)=2^(x+1),则f^-1 (4)等于?

人气：244 ℃　时间：2020-02-04 04:16:51

解答

y=2^(x+1)
x = -1 + log2(y)
所以,f-1(x)=-1 + log2(x)
f-1(4) = -1 + log2(4) = -1 + 2 = 1