From http://www.w3schools.com (Copyright Refsnes Data)

JavaScript sqrt() Method

Math Object Reference

JavaScript Math Object

Definition and Usage

The sqrt() method returns the square root of a number.

Syntax

Math.sqrt(x)

Parameter	Description
x	Required. A number

Tips and Notes

Note: The sqrt() method will return NaN if the parameter x is a negative number.

Example

Example

Return the square root of different numbers:

<script type="text/javascript">

document.write(Math.sqrt(0) + "<br />");
document.write(Math.sqrt(1) + "<br />");
document.write(Math.sqrt(9) + "<br />");
document.write(Math.sqrt(0.64) + "<br />");
document.write(Math.sqrt(-9));

</script>

The output of the code above will be:

0
1
3
0.8
NaN

Try it yourself »

Math Object Reference

JavaScript Math Object

From http://www.w3schools.com (Copyright Refsnes Data)