Solving Quadratic Formula with Bhaskara

example.php

<?php
print_r(quadEq(1, 2, 1));// a=1 b=2 c=3 (x² + 2x + 3 = 0)
//Result: array(-1)

quadEq.php

<?php
// Using Bhaskara
function quadEq($a, $b, $c) {
    $delta = pow($b, 2) - (4 * $a * $c);

    if ($delta >= 0) {
        if ($delta == 0) {
            $x = -$b / 2 * $a;
            return array($x);
        }
	  
        $x1 = (-$b + sqrt($delta)) / 2 * $a;
        $x2 = (-$b - sqrt($delta)) / 2 * $a;
        return array($x1, $x2);
    }
	
    return array('NAN', 'NAN');
}