/JavaScript

# Math.sqrt()

The Math.sqrt() function returns the square root of a number, that is

$∀ x ≥ 0 , M a t h . s q r t ( x ) = x = the unique y ≥ 0 such that y 2 = x \forall x \geq 0, \mathtt{Math.sqrt(x)} = \sqrt{x} = \text{the unique} ; y \geq 0 ; \text{such that} ; y^2 = x$

## Syntax

Math.sqrt(x)


### Parameters

x

A number.

### Return value

The square root of the given number. If the number is negative, NaN is returned.

## Description

If the value of x is negative, Math.sqrt() returns NaN.

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

## Examples

### Using Math.sqrt()

Math.sqrt(9); // 3
Math.sqrt(2); // 1.414213562373095

Math.sqrt(1);  // 1
Math.sqrt(0);  // 0
Math.sqrt(-1); // NaN
Math.sqrt(-0); // -0


## Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet Deno Node.js
sqrt
1
12
1
3
3
1
4.4
18
4
10.1
1
1.0
1.0
0.10.0