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The Math.cbrt() function returns the cube root of a number, that is

Math.cbrt(x)=x3=the uniqueysuch thaty3=x\mathtt{Math.cbrt(x)} = \sqrt[3]{x} = \text{the unique} \; y \; \text{such that} \; y^3 = x

Syntax

Math.cbrt(x)

Parameters

x
A number.

Return value

The cube root of the given number.

Description

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

Examples

Using Math.cbrt()

Math.cbrt(NaN); // NaN
Math.cbrt(-1); // -1
Math.cbrt(-0); // -0
Math.cbrt(-Infinity); // -Infinity
Math.cbrt(0); // 0
Math.cbrt(1); // 1
Math.cbrt(Infinity); // Infinity
Math.cbrt(null); // 0
Math.cbrt(2);  // 1.2599210498948732

Polyfill

For all x0x \geq 0, have x3=x1/3\sqrt[3]{x} = x^{1/3} so this can be emulated by the following function:

if (!Math.cbrt) {
  Math.cbrt = (function(pow) {
    return function cbrt(){
      // ensure negative numbers remain negative:
      return x < 0 ? -pow(-x, 1/3) : pow(x, 1/3);
    };
  })(Math.pow); // localize Math.pow to increase efficiency
}

Specifications

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Math.cbrt' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of 'Math.cbrt' in that specification.
Draft  

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
cbrtChrome Full support 38Edge Full support 12Firefox Full support 25IE No support NoOpera Full support 25Safari Full support 8WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 25Opera Android Full support YesSafari iOS Full support 8Samsung Internet Android Full support Yesnodejs Full support 0.12

Legend

Full support  
Full support
No support  
No support

See also

Document Tags and Contributors

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