<?php
/**
 * ax² + bx + c = 0 solver
 * 
 * @author agrafix.net
 */
header("Content-Type: text/plain;charset=utf-8");
 
// input -> ax² + bx + c = 0
$a = 1;
$b = 3;
$c = 1;
 
// calc
print "Eq: ".$a."x² + ".$b."x + ".$c." = 0\n";
 
$d = pow($b, 2) - 4*$a*$c;
print "D = $d\n";
 
if ($d < 0) {
	print "L = {}";
}
else {
 
	$x1 = (-$b + sqrt($d)) / (2 * $a);
	$x2 = (-$b - sqrt($d)) / (2 * $a);
 
	if ($x1 == $x2) {
		print "L = {".round($x1, 4)."}";
	}
	else {
		print "L = {".round($x1, 4).", ".round($x2, 4)."}";
	}
}
?>