Cosh
From specialfunctionswiki
The hyperbolic cosine function $\cosh \colon \mathbb{C} \rightarrow \mathbb{C}$ is defined by
$$\mathrm{cosh}(z)=\dfrac{e^z + e^{-z}}{2}$$
Domain coloring of analytic continuation of $\cosh$.
Properties
Derivative of cosh
Pythagorean identity for sinh and cosh
Weierstrass factorization of cosh
Relationship between cosh and hypergeometric 0F1
Relationship between Bessel I sub 1/2 and cosh
Relationship between cosh and cos
Relationship between cos and cosh
Relationship between secant, Gudermannian, and cosh
Relationship between cosh, inverse Gudermannian, and sec