C#Basics HW4 Problem6 - advanced

using System;
using System.Numerics;
class GeneralizedQuadraticEquation
{
    static void Main()
    {
        Console.WriteLine("This program solves  general (non-real roots included) quadratic equations of the form ax^2 + bx + c = 0");
        Console.Write("Please enter coefficient a: ");
        double a = double.Parse(Console.ReadLine());
        Console.Write("Please enter coefficient b: ");
        double b = double.Parse(Console.ReadLine());
        Console.Write("Please enter coefficient c: ");
        double c = double.Parse(Console.ReadLine());
        double discriminant = b * b - 4 * a * c;     //calculations start here
        Complex squarerootDiscriminant = Complex.Sqrt(discriminant);
        if (discriminant == 0)
        {
            double x = -b / 2 / a;
            Console.WriteLine("Double root x1 = x2 = {0}", x);
        }
        else
        {
            Complex x1 = (-b - squarerootDiscriminant) / 2 / a;
            Complex x2 = (-b + squarerootDiscriminant) / 2 / a;
            Console.WriteLine("The solution of the equation is : x1 = {0}, \r\n x2 = {1}", x1, x2);
        }
    }
}