# Definition:Hyperbolic Cosine/Real

## Definition

The real hyperbolic cosine function is defined on the real numbers as:

$\cosh: \R \to \R$:
$\forall x \in \R: \cosh x := \dfrac {e^x + e^{-x} } 2$

## Also see

• Results about the hyperbolic cosine function can be found here.