Definition:Inverse Hyperbolic Tangent/Complex/Principal Branch

Definition

The principal branch of the complex inverse hyperbolic tangent function is defined as:

$\forall z \in \C: \map \Artanh z := \dfrac 1 2 \, \map \Ln {\dfrac {1 + z} {1 - z} }$

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

Also see

• Derivation of Area Hyperbolic Tangent from Inverse Hyperbolic Tangent Multifunction

Sources

• 1981: Murray R. Spiegel: Theory and Problems of Complex Variables (SI ed.) ... (previous) ... (next): $2$: Functions, Limits and Continuity: The Elementary Functions: $8$