How do I compute the real and imaginary parts of the complex number, $z = \tan (x + ix)$

Question

Using the Wolfram Alpha website, the site gave me three alternate forms of $z = \tan (x + ix)$, but my concern is on the third alternate form which has to do with $\sin (x)$, $\cos (x)$, $\sinh (x)$, and $\cosh (x)$. The question here is: How can I obtain that alternate form of $\tan (x + ix)$ mathematically?