Difference of cosh and sinh

Theorem

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

References

• 1964: Milton Abramowitz and Irene A. Stegun: Handbook of mathematical functions ... (previous) ... (next): $4.5.20$