PHP sqrt()Functions

PHP Math 参考手册PHP Math Reference Manual

Examples

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));
?>

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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: Returnsnumberthe square root of, ifnumberis negative, returns NAN.
Return type: Float
PHP Version: 4+


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