Definition:Inverse Hyperbolic Sine/Complex/Principal Branch

Definition
The principal branch of the inverse hyperbolic sine function is defined as:
 * $\operatorname{arcsinh} \left({z}\right) = \ln \left({z + \sqrt{z^2 + 1} }\right)$

Also see

 * Derivation of Hyperbolic Arcsine from Inverse Hyperbolic Sine Multifunction