Definition:Inverse Tangent/Complex/Definition 1

Definition
Let $z \in \C$ be a complex number.

The inverse tangent of $z$ is the multifunction defined as:
 * $\tan^{-1} \left({z}\right) := \left\{{w \in \C: \tan \left({w}\right) = z}\right\}$

where $\tan \left({w}\right)$ is the tangent of $w$.

Also see

 * Equivalence of Definitions of Complex Inverse Tangent Function


 * Definition:Complex Arctangent