Simpson's Formulas/Hyperbolic Cosine by Hyperbolic Cosine

Theorem

 * $\cosh x \cosh y = \dfrac {\cosh \paren {x + y} + \cosh \paren {x - y} } 2$

where $\cosh$ denotes hyperbolic cosine.

Also presented as
This result can also be seen presented as:


 * $2 \cosh x \cosh y = \cosh \paren {x + y} + \cosh \paren {x - y}$