---
title: Math.tanh()
slug: Web/JavaScript/Reference/Global_Objects/Math/tanh
translation_of: Web/JavaScript/Reference/Global_Objects/Math/tanh
---
<div>{{JSRef}}</div>

<p>A função <strong><code>Math.tanh()</code></strong>  retorna a tangente hiperbólica de um número, que é:</p>

<p><math display="block"><semantics><mrow><mo lspace="0em" rspace="0em">tanh</mo><mi>x</mi><mo>=</mo><mfrac><mrow><mo lspace="0em" rspace="0em">sinh</mo><mi>x</mi></mrow><mrow><mo lspace="0em" rspace="0em">cosh</mo><mi>x</mi></mrow></mfrac><mo>=</mo><mfrac><mrow><msup><mi>e</mi><mi>x</mi></msup><mo>-</mo><msup><mi>e</mi><mrow><mo>-</mo><mi>x</mi></mrow></msup></mrow><mrow><msup><mi>e</mi><mi>x</mi></msup><mo>+</mo><msup><mi>e</mi><mrow><mo>-</mo><mi>x</mi></mrow></msup></mrow></mfrac><mo>=</mo><mfrac><mrow><msup><mi>e</mi><mrow><mn>2</mn><mi>x</mi></mrow></msup><mo>-</mo><mn>1</mn></mrow><mrow><msup><mi>e</mi><mrow><mn>2</mn><mi>x</mi></mrow></msup><mo>+</mo><mn>1</mn></mrow></mfrac></mrow><annotation encoding="TeX">\tanh x = \frac{\sinh x}{\cosh x} = \frac {e^x - e^{-x}} {e^x + e^{-x}} = \frac{e^{2x} - 1}{e^{2x}+1}</annotation></semantics></math></p>

<div>{{EmbedInteractiveExample("pages/js/math-tanh.html")}}</div>

<h2 id="Syntax">Syntax</h2>

<pre class="syntaxbox"><code>Math.tanh(<var>x</var>)</code></pre>

<h3 id="Parameters">Parameters</h3>

<dl>
 <dt><code>x</code></dt>
 <dd>Um número.</dd>
</dl>

<h3 id="Return_value">Return value</h3>

<p>Uma tangente hiperbólica de um número dado.</p>

<h2 id="Description">Description</h2>

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

<h2 id="Examples">Examples</h2>

<h3 id="Using_Math.tanh()">Using <code>Math.tanh()</code></h3>

<pre class="brush: js">Math.tanh(0);        // 0
Math.tanh(Infinity); // 1
Math.tanh(1);        // 0.7615941559557649
</pre>

<h2 id="Polyfill">Polyfill</h2>

<p>This can be emulated with the help of the {{jsxref("Math.exp()")}} function:</p>

<pre class="brush: 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);
}
</pre>

<h2 id="Specifications">Specifications</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('ES2015', '#sec-math.tanh', 'Math.tanh')}}</td>
   <td>{{Spec2('ES2015')}}</td>
   <td>Initial definition.</td>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-math.tanh', 'Math.tanh')}}</td>
   <td>{{Spec2('ESDraft')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Compatibilidade com navegadores</h2>

<p>{{Compat("javascript.builtins.Math.tanh")}}</p>

<h2 id="See_also">See also</h2>

<ul>
 <li>{{jsxref("Math.acosh()")}}</li>
 <li>{{jsxref("Math.asinh()")}}</li>
 <li>{{jsxref("Math.atanh()")}}</li>
 <li>{{jsxref("Math.cosh()")}}</li>
 <li>{{jsxref("Math.sinh()")}}</li>
</ul>