# Math.tanh()

## BaselineWidely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

A função Math.tanh() retorna a tangente hiperbólica de um número, que é:

$tanh x = sinh x cosh x = e x - e - x e x + e - x = e 2 x - 1 e 2 x + 1 \tanh x = \frac{\sinh x}{\cosh x} = \frac {e^x - e^{-x}} {e^x + e^{-x}} = \frac{e^{2x} - 1}{e^{2x}+1}$

## Syntax

Math.tanh(x)


### Parameters

x

Um número.

### Return value

Uma tangente hiperbólica de um número dado.

## 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()

js
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:

js
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);
};


## Especificações

Specification
ECMAScript Language Specification
# sec-math.tanh