static double GetDiscriminant(double a, double b, double c) {
return b * b - 4 * a * c;
public static void Main()
double a = 2, b = 4, c = 2;
double d = GetDiscriminant(a,b,c);
Console.WriteLine("d: {0}",d);
double root1 = (-b + Math.Sqrt(d))/(2*a);
double root2 = (-b - Math.Sqrt(d))/(2*a);
Console.WriteLine("Roots: {0},{1}",root1,root2);
Console.WriteLine("Double root: {0}",root);
Console.WriteLine("No real roots");