-----------FORM------------


<form action="/files/solvequadratic.php" method="post">
a: <input type="text" name="a" size="15" maxlength="14" /><br />
b: <input type="text" name="b" size="15" maxlength="14" /><br />
c: <input type="text" name="c" size="15" maxlength="14" /><br />
<input type="submit" value="Solve!" /><input type="reset" value="Reset!" />
</form>



---------------quadratic.php---------------

<?php 
$a = $_POST["a"];
$b = $_POST["b"];
$c = $_POST["c"];
$d = pow($b,2) - 4*$a*$c;
echo "You entered a = $a, b = $b, and c = $c. <br /><br />";

if ($d < 0)
	{
	echo "The equation has no real solutions.";
	}
elseif ($a == 0)
	{
	echo "That is not a quadratic equation.";
	}
elseif ($d == 0)
	{
	echo "The equation has one solution. <br />";
	$x = ((-$b)+sqrt($d))/(2*$a);
	echo "X = $x";
	}
else
	{
	echo "The equation has two solutions. <br />";
	$x1 = ((-$b) + sqrt($d)) / (2*$a);
	$x2 = ((-$b) - sqrt($d)) / (2*$a);
	echo "X1 = $x1 <br />";
	echo "X2 = $x2";
	}
?>