Consider f(x)=ln(x+x2+1)f(x) = \ln(x + \sqrt{x^2+1})f(x)=ln(x+x2+1). Find f−1(x)f^{-1}(x)f−1(x).
ex−e−x2\frac{e^x - e^{-x}}{2}2ex−e−x
ex+e−x2\frac{e^x + e^{-x}}{2}2ex+e−x
ex−1e^x - 1ex−1
ln(x+x2−1)\ln(x + \sqrt{x^2-1})ln(x+x2−1)