files/en-us/web/javascript/reference/global_objects/math/sqrt/index.md

metadata

title: Math.sqrt()
short-title: sqrt()
slug: Web/JavaScript/Reference/Global_Objects/Math/sqrt
page-type: javascript-static-method
browser-compat: javascript.builtins.Math.sqrt
sidebar: jsref

The Math.sqrt() static method returns the square root of a number. That is

$$\forall x\ge 0,𝙼𝚊𝚝𝚑.𝚜𝚚𝚛𝚝(𝚡)=\sqrt{x}=\text{the unique }y\ge 0\text{ such that }{y}^2=x\backslash forall\; x\; \backslash geq\; 0,\backslash ;\backslash mathtt\{\backslash operatorname\{Math.sqrt\}(x)\}\; =\; \backslash sqrt\{x\}\; =\; \backslash text\{the\; unique\; \}\; y\; \backslash geq\; 0\; \backslash text\{\; such\; that\; \}\; y^2\; =\; x$$

{{InteractiveExample("JavaScript Demo: Math.sqrt()")}}

function calcHypotenuse(a, b) {
  return Math.sqrt(a * a + b * b);
}

console.log(calcHypotenuse(3, 4));
// Expected output: 5

console.log(calcHypotenuse(5, 12));
// Expected output: 13

console.log(calcHypotenuse(0, 0));
// Expected output: 0

Syntax

Math.sqrt(x)

Parameters

• x
  • : A number greater than or equal to 0.

Return value

The square root of x, a nonnegative number. If x < 0, returns {{jsxref("NaN")}}.

Description

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(-1); // NaN
Math.sqrt(-0); // -0
Math.sqrt(0); // 0
Math.sqrt(1); // 1
Math.sqrt(2); // 1.414213562373095
Math.sqrt(9); // 3
Math.sqrt(Infinity); // Infinity

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{jsxref("Math.cbrt()")}}
• {{jsxref("Math.exp()")}}
• {{jsxref("Math.log()")}}
• {{jsxref("Math.pow()")}}