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

Specifications

Specification
ECMAScript Language Specification (ECMAScript)
#sec-math.sqrt

Browser compatibility

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See also