# Math.tanh()

The Math.tanh() function returns the hyperbolic tangent of a number, that is

$tanhx=sinhxcoshx=ex-e-xex+e-x=e2x-1e2x+1\tanh x = \frac{\sinh x}{\cosh x} = \frac {e^x - e^{-x}} {e^x + e^{-x}} = \frac{e^{2x} - 1}{e^{2x}+1}$

## Syntax

Math.tanh(x)

### Parameters

x
A number.

### Return value

The hyperbolic tangent of the given number.

## Description

Because tanh() is a static method of Math, you always use it as Math.tanh(), rather than as a method of a Math object you created (Math is not a constructor).

## Examples

### Using Math.tanh()

Math.tanh(0);        // 0
Math.tanh(Infinity); // 1
Math.tanh(1);        // 0.7615941559557649


## Polyfill

This can be emulated with the help of the Math.exp() function:

Math.tanh = Math.tanh || function(x){
var a = Math.exp(+x), b = Math.exp(-x);
return a == Infinity ? 1 : b == Infinity ? -1 : (a - b) / (a + b);
}


## Specifications

Specification
ECMAScript Latest Draft (ECMA-262)
The definition of 'Math.tanh' in that specification.

## Browser compatibility

Update compatibility data on GitHub
Desktop Mobile Server Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Chrome Full support 38 Edge Full support 12 Firefox Full support 25 IE No support No Opera Full support 25 Safari Full support 8 WebView Android Full support 38 Chrome Android Full support 38 Firefox Android Full support 25 Opera Android Full support 25 Safari iOS Full support 8 Samsung Internet Android Full support 3.0 nodejs Full support 0.12

Full support
Full support
No support
No support