Sum of Hyperbolic Sine and Cosine equals Exponential

Theorem
Let $z \in \C$ be a complex number.

Then:
 * $e^z = \cosh z + \sinh z$

where:
 * $e^z$ denotes the complex exponential function
 * $\cosh z$ denotes the cosine function
 * $\sinh z$ denotes sine function

Also see

 * Euler's Formula