JavaScript - Math sqrt Method

Description

This method returns the square root of a number. If the value of a number is negative, sqrt returns NaN.

Syntax

Its syntax is as follows −

Math.sqrt( x ) ;

Parameter Details

x − A number

Return Value

Returns the square root of a given number.

Example

Try the following example program.

<html>
   
   <head>
      <title>JavaScript Math sqrt() Method</title>
   </head>
   
   <body>
      
      <script type="text/javascript">
         var value = Math.sqrt( 0.5 );
         document.write("First Test Value : " + value );
         
         var value = Math.sqrt( 81 );
         document.write("<br />Second Test Value : " + value ); 
         
         var value = Math.sqrt( 13 );
         document.write("<br />Third Test Value : " + value ); 
         
         var value = Math.sqrt( -4 );
         document.write("<br />Fourth Test Value : " + value ); 
      </script>
      
   </body>
</html>

Output

First Test Value : 0.7071067811865476
Second Test Value : 9
Third Test Value : 3.605551275463989
Fourth Test Value : NaN