Definition:Inverse Hyperbolic Cotangent/Complex/Principal Branch

Definition
The principal branch of the complex inverse hyperbolic cotangent function is defined as:
 * $\forall z \in \C: \map {\Coth^{-1} } z := \dfrac 1 2 \, \map \Ln {\dfrac {z + 1} {z - 1} }$

where $\Ln$ denotes the principal branch of the complex natural logarithm.

Also see

 * Derivation of Hyperbolic Arccotangent from Inverse Hyperbolic Cotangent Multifunction