(PHP 4, PHP 5, PHP 7, PHP 8)
sqrt — Square root
$num): float
Returns the square root of num.
numThe argument to process
The square root of num
or the special value NAN for negative numbers.
Example #1 sqrt() example
<?php
// Precision depends on your precision directive
echo sqrt(9); // 3
echo sqrt(10); // 3.16227766 ...
?>
M_SQRTPI - sqrt(pi)M_2_SQRTPI - 2/sqrt(pi)M_SQRT2 - sqrt(2)M_SQRT3 - sqrt(3)M_SQRT1_2 - 1/sqrt(2)