# Definition:Hyperbolic Tangent/Real

## Definition

### Definition 1

The real hyperbolic tangent function is defined on the real numbers as:

$\tanh: \R \to \R$:
$\forall x \in \R: \tanh x := \dfrac {e^z - e^{-x} } {e^z + e^{-x} }$

### Definition 2

The real hyperbolic tangent function is defined on the real numbers as:

$\tanh: \R \to \R$:
$\forall x \in \R: \tanh x := \dfrac {\sinh x} {\cosh x}$

where:

$\sinh$ is the real hyperbolic sine
$\cosh$ is the real hyperbolic cosine

## Also denoted as

The notation $\operatorname {th} z$ can also be found for hyperbolic tangent.

## Also see

• Results about the hyperbolic tangent function can be found here.

## Linguistic Note

The usual symbol tanh for hyperbolic tangent is awkward to pronounce.

Some pedagogues say it as tansh, and some as than (where the th is voiceless as in thin, for example).

Others prefer the mouthful which is hyperbolic tan