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<sinhtan>
^Math FunctionsLast updated: Mon, 26 Oct 2026

sqrt

(PHP 4, PHP 5, PHP 7, PHP 8)

sqrt — Square root

Description

function sqrt(float $num): float

Returns the square root of num.

Parameters

num

The argument to process

Return Values

The square root of num or the special value NAN for negative numbers.

Examples

Example #1 sqrt() example

<?php
// Precision depends on your precision directive
echo sqrt(9), PHP_EOL; // 3
echo sqrt(10), PHP_EOL; // 3.16227766 ...
?>

See Also


<sinhtan>
^Math FunctionsLast updated: Mon, 26 Oct 2026