What is the inverse of the function $f(x)=\large\frac{e^x-e^{-x}}{e^x+e^{-x}}$

Question

$\begin{array}{1 1}f^{-1}(x)=\log\large\big(\frac{1-x}{1+x}\big) \\f^{-1}(x)=\frac{1}{2}\log\large\big(\frac{1+x}{1-x}\big) \\ f^{-1}(x)=\frac{1}{2}\log\large\big(\frac{1-x}{1+x}\big) \\f^{-1}(x)=\log\large\big(\frac{1+x}{1-x}\big)\end{array}$