Definition:Inverse Hyperbolic Cosine/Real/Definition 1

Definition
Let $S$ denote the subset of the real numbers:
 * $S = \set {x \in \R: x \ge 1}$

The inverse hyperbolic cosine $\arcosh: S \to \R$ is a real function defined on $S$ as:


 * $\forall x \in S: \map \arcosh x := y \in \R_{\ge 0}: x = \map \cosh y$

where $\map \cosh y$ denotes the hyperbolic cosine function.

Also see

 * Equivalence of Definitions of Real Inverse Hyperbolic Cosine