Please help me to prove this..

If $\displaystyle \cos(\theta + i\phi)=\sec(\alpha + i\beta)$, then prove that $\displaystyle \tanh^{2}\phi\cosh^{2}\beta=\sin^{2}\alpha$ and $\displaystyle \tanh^{2}\beta\cosh^{2}\phi=\sin^{2}\theta$

Thanks in advance..