Math.tanh()
The Math.tanh()
function returns the hyperbolic tangent of a number, that is
Syntax
JavaScript
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Math.tanh(<var>x</var>)
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()
JavaScript
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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:
JavaScript
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Math.tanh = Math.tanh || function(x) { if (x === Infinity) { return 1; } else if (x === -Infinity) { return -1; } else { return (Math.exp(x) - Math.exp(-x)) / (Math.exp(x) + Math.exp(-x)); } }
or using only one call to Math.exp()
:
JavaScript
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Math.tanh = Math.tanh || function(x) { if (x === Infinity) { return 1; } else if (x === -Infinity) { return -1; } else { var y = Math.exp(2 * x); return (y - 1) / (y + 1); } }
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Math.tanh' in that specification. |
Standard | Initial definition. |
ECMAScript 2017 Draft (ECMA-262) The definition of 'Math.tanh' in that specification. |
Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 38 | 25 (25) | No support | 25 | 7.1 |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | No support | No support | 25.0 (25) | No support | No support | 8 |
See also
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/javascript/reference/global_objects/math/tanh