Find the second order derivatives of the functions given in $ \tan^{-1} x $

Question

$\begin{array}{1 1} \large\frac{2x}{(1-x^2)^2}\\\large\frac{-2x}{(1+x^2)^2} \\ \large\frac{-2x}{(1+x^2)^3} \\(1+x^2)^{-1} \end{array} $