04.ConsoleInputOutputHomework/06.QuadraticEquation

//Problem 6.    Quadratic Equation
//Write a program that reads the coefficients a, b and c of a quadratic equation ax2 + bx + c = 0 and solves it (prints its real roots).

using System;

class QuadraticEquation
{
    static void Main()
    {
        Console.Write("Please, enter the coefficient a:");
        double a = double.Parse(Console.ReadLine());
        Console.Write("Please, enter the coefficient b:");
        double b = double.Parse(Console.ReadLine());
        Console.Write("Please, enter the coefficient c:");
        double c = double.Parse(Console.ReadLine());
        Console.WriteLine("Equation: {0}X^2+{1}X+{2}=0", a, b, c);
        Console.Write("Result:");
        if (a == 0)
        {
            double result = -(c / b);
            Console.WriteLine("There is one root - x1 = {0}", result);
        }
        double discriminant = b * b - 4 * a * c;
        if (discriminant > 0)
        {
            double xOne = (-b + Math.Sqrt(discriminant)) / 2 * a;
            double xTwo = (-b - Math.Sqrt(discriminant)) / 2 * a;
            Console.WriteLine("There are two real roots - x1: {0} and x2: {1}", xOne, xTwo);
        }
        else if (discriminant == 0)
        {
            double xOne = -(b / 2 * a);
            Console.WriteLine("There is one real root - x1: {0}.", xOne);
        }
        else
        {
            Console.WriteLine("There are no real roots.");
        }
    }
}