if tan(pi/4+y/2)=tan(pi/4+x/2)^3 find sinx*(3+sin^2x)/(1+3*sin^2x)

In the first step use formula of tan and then square both sides you will get 1+siny\1-siny= (1+sin)/1-sinx)^3 now use componendo and dividendo will get the desired results