Tanh

Often used as a Activation Function. Returns from -1 to 1

$\tanh x$

$\tanh x=\frac{\sinh x}{\cosh x}$ ${\tanh }^{\prime }x=sec{h}^2(x)$ ${\tanh }^{-1}=\frac{1}{2}\ln (\frac{1+x}{1-x})$ $({\tanh }^{-1}{)}^{\prime }x=\frac{1}{1-x^2}$