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sqrt

PHP function Edit on GitHub ✎

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

Square root

Description

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

sqrt() example

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

See Also

  • pow()
  • M_SQRTPI - sqrt(pi)
  • M_2_SQRTPI - 2/sqrt(pi)
  • M_SQRT2 - sqrt(2)
  • M_SQRT3 - sqrt(3)
  • M_SQRT1_2 - 1/sqrt(2)

Source: reference/math/functions/sqrt.xml · from the official PHP manual (php/doc-en)