Sum of cosh and sinh

Theorem

The following formula holds: $$\cosh(z) + \sinh(z) = e^z,$$ where $\cosh$ denotes hyperbolic cosine, $\mathrm{sinh}$ denotes hyperbolic sine, and $e^z$ denotes the exponential.

References

• 1964: Milton Abramowitz and Irene A. Stegun: Handbook of mathematical functions ... (previous) ... (next): $4.5.19$