JavaScript Math.sqrt() Method

The Math.sqrt() method in JavaScript is used to calculate the square root of a non-negative number.

Syntax

Math.sqrt(x);

Parameters

• x (Required): A number representing the value for which you want to compute the square root. This number must be non-negative because the square root of negative numbers is not a real number (it could be a complex number). If the argument is negative, the result will be NaN (Not-a-Number).

Return Value

• Positive Number: If x is a non-negative number, Math.sqrt(x) returns the square root of x.
• NaN: If x is negative, the method returns NaN (Not-a-Number), because square roots of negative numbers are not real numbers in the realm of real-number arithmetic.

Example 1: Basic example to use Math.sqrt() to get the square root of a number.

let result = Math.sqrt(9);
console.log(result); // Output: 3

result = Math.sqrt(0);
console.log(result); // Output: 0

result = Math.sqrt(1);
console.log(result); // Output: 1

Example 2: Square root of Negative Input

let result = Math.sqrt(-4);
console.log(result); // Output: NaN

In this case, the argument is negative, so Math.sqrt() returns NaN because the square root of a negative number is not a real number.

Example 3: Square Root of a Large Number

let result = Math.sqrt(1000000);
console.log(result); // Output: 1000

The square root of 1,000,000 is 1,000.

Example 4: Square Root of Infinity

let result = Math.sqrt(Infinity);
console.log(result); // Output: Infinity

The square root of Infinity is still Infinity.

Example 5: Using Variables with Math.sqrt()

let x = 16;
let result = Math.sqrt(x);
console.log(result); // Output: 4

You can pass variables to Math.sqrt() as well. In this case, the square root of 16 is 4.

Supported Browsers

Browser	Version Supported
Chrome	1.0+
Firefox	1.0+
Safari	1.0+
Edge	12+
Internet Explorer	6+
Opera	7.0+