Prove that `tan{1/2sin^(-1)((2x)/(1-x^(2))+1/2cos^(-1)((1-y^(2))/(1+y^(2))}=(x+xy)/(1-xy)`, where

Prove that `tan{1/2sin^(-1)((2x)/(1-x^(2))+1/2cos^(-1)((1-y^(2))/(1+y^(2))}=(x+xy)/(1-xy)`, where `|x| lt 1,y gt 0` and `xy lt 1`.