Algorithme

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

<html>
<head>
	<title>Untitled</title>
	<style>
		table, tr{
			background-color: #4444ff;
		}
		#tdHover{
			background-color:#8888ff;
			color: #eeeeee;
		}
		a{
			text-decoration: none;
		}
		a:hover{
			color: #ffffff;
		}
	</style>
	<script>
		function getResult(a,b,c){
			//Roots = (-b +/- Sqrt(b*b-4*a*c))  /  (2*a)
			equation=""+a+"x² + "+b+"x + "+c+" = 0";
			html  = "L'équation '"+equation+"' <br/>";
			if(a==0){
				root = -1*c/b;
				html += "admet une seule racine [x = -c / b]: " + root;		
			}else if(b*b!=4*a*c){
				root  = (-1*parseInt(b))/(2*parseInt(a));
				html += "admet une seule racine [x = -b / 2a]: " + root;
			}else if(b*b < 4*a*c){
				html += "n'admet pas de racine";
			}else{
				root1 = (-b + Math.sqrt(b*b-4*a*c))/(2*a);
				root2 = (-b - Math.sqrt(b*b-4*a*c))/(2*a);
				html += "admet deux racines <br/>";
				html += "[x1 = (-b + Sqrt(b*b-4*a*c) / 2a]: " + root1 + "<br/>";
				html += "[x2 = (-b - Sqrt(b*b-4*a*c) / 2a]: " + root2;
			}
			document.getElementsByName("result")[0].innerHTML=html;
		}
	</script>
</head>

<body>
<form>
	<input type="text"  name="aValue" id="aValue"/> x² + <input type="text" name="bValue" id="bValue"/> x + <input type="text" name="cValue" id="cValue"/> = 0
<p/>
<button onclick="getResult(document.getElementsByName('aValue')[0].value, document.getElementsByName('bValue')[0].value, document.getElementsByName('cValue')[0].value);">Calculer les racines</button>
</form>
<div name="result" id="result" style=""background-color: #dddddd; width: 480; height: 100; border-style: solid;border-width: 1px; border-color: #444444;">
</div>

</body>
</html>