W3cubDocs

/JavaScript

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).

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);
}

Examples

Using Math.tanh()

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

Specifications

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
tanh 38 12 25 No 25 8
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
tanh 38 38 25 25 8 3.0
Server
Node.js
tanh 0.12

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/tanh