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PHP sqrt() Function

❮ PHP Math Reference

Example

Return the square root of different numbers:

<?php
echo(sqrt(0) . "<br>");
echo(sqrt(1) . "<br>");
echo(sqrt(9) . "<br>");
echo(sqrt(0.64) . "<br>");
echo(sqrt(-9));
?>
Run example »

Definition and Usage

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


Syntax

sqrt(number);

Parameter Description
number Required. Specifies a number

Technical Details

Return Value: The square root of number, or NAN for negative numbers
Return Type: Float
PHP Version: 4+

❮ PHP Math Reference