Hello. I`m having trouble to prove this coplex identities,using the exponencial forms:

1)$\displaystyle \tan(z1+z2) = \frac {\tan(z1)+tan(z2)} {1- \tan(z1)* \tan(z2)}$

2)$\displaystyle \tan(\frac{z}{2})=\frac{\sin(z)}{1+\cos(z)}$

where z is a complex number x+iy

Thanks!