Find the value of $\tan \bigg[\sin^{-1}\bigg(\large\frac{2x}{1+x^2}\bigg)+$$\cos^{-1} \bigg( \large\frac{1-y^2}{1+y^2}\bigg)\bigg]$

Question

$\begin{array}{1 1} 0 \\ \large\frac{x}{y} \\ \large\frac{x+y}{1-xy} \\ 2 \end{array}$