Cosh

$\cosh x$

$\cosh x=\frac{e^x+e^{-x}}{2}$ ${\cosh }^{\prime }x=\sinh x$ ${\cosh }^{-1}x=\ln (x+\sqrt{x^2-1})$ $({\cosh }^{-1}{)}^{\prime }x=\frac{1}{\sqrt{x^2-1}}$ These are used to model Catenary shapes

Range

$\cosh \ge 1$