Calculate Quadratic Equation

/*
 *Write a program that enters the coefficients a, b and c of a quadratic equation
        a*x2 + b*x + c = 0
        and calculates and prints its real roots. Note that quadratic equations may have 0, 1 or 2 real roots.

 */

using System;

class CalculateQuadraticEquation
{
    static void Main()
    {
        double coefficientA, coefficientB, coefficientC, discriminantD, DRoot2, resultX1, resultX2;

        string invalidInput = "Invalid input! Please enter value between " + double.MinValue + " and " + double.MaxValue + "!" + Environment.NewLine; ;
        Console.WriteLine("ax^2 + bx + c = 0, a != 0");
        Console.WriteLine("Enter value of coefficient a: a = ");
        while (!(double.TryParse(Console.ReadLine(), out coefficientA) && coefficientA >= double.MinValue && coefficientA <= double.MaxValue))
        {
            Console.WriteLine(invalidInput);
            Console.WriteLine("Enter value of coefficient a: a = ");
        }

        Console.WriteLine("Enter value of coefficient b: b = ");
        while (!(double.TryParse(Console.ReadLine(), out coefficientB) && coefficientB >= double.MinValue && coefficientB <= double.MaxValue))
        {
            Console.WriteLine(invalidInput);
            Console.WriteLine("Enter value of coefficient b: b = ");
        }

        Console.WriteLine("Enter value of coefficient c: c = ");
        while (!(double.TryParse(Console.ReadLine(), out coefficientC) && coefficientC >= double.MinValue && coefficientC <= double.MaxValue))
        {
            Console.WriteLine(invalidInput);
            Console.WriteLine("Enter value of coefficient c: c = ");
        }

        if (coefficientA != 0)
        {
            discriminantD = (Math.Pow(coefficientB, 2)) - (4 * coefficientA * coefficientC);

            if (discriminantD < 0)
            {
                Console.WriteLine("The quadratic equation {0}x^2 + {1}x + {2} = 0 has no real roots because discriminant D = {3}" + Environment.NewLine, coefficientA, coefficientB, coefficientC, discriminantD);
            }
            if (discriminantD > 0)
            {
                DRoot2 = Math.Sqrt(discriminantD);
                resultX1 = (((-1) * coefficientB) + DRoot2) / (2 * coefficientA);
                resultX2 = (((-1) * coefficientB) - DRoot2) / (2 * coefficientA);

                Console.WriteLine("The quadratic equation {0}x^2 + {1}x + {2} = 0 has two real roots: x1 = {3} and x2 = {4} and discriminant D = {5} !" + Environment.NewLine, coefficientA, coefficientB, coefficientC, resultX1, resultX2, discriminantD);
            }
            if (discriminantD == 0)
            {
                resultX1 = (((-1) * coefficientB)) / (2 * coefficientA);
                Console.WriteLine("The quadratic equation {0}x^2 + {1}x + {2} = 0 has one real root: x1 = {3} and discriminant D = {4} !" + Environment.NewLine, coefficientA, coefficientB, coefficientC, resultX1, discriminantD);
            }
        }
        else
        {
            if (coefficientB != 0)
            {
                resultX1 = (-1) * coefficientC / coefficientB;
                Console.WriteLine("{0}x + {1} = 0 is not quadratic equation!" + Environment.NewLine + "After all: x = {2}" + Environment.NewLine, coefficientB, coefficientC, resultX1);
            }
            else
            {
                if (coefficientC != 0)
                {
                    Console.WriteLine("Can't divide by 0! The equation has no solution!" + Environment.NewLine);
                }
                else
                {
                    Console.WriteLine("The equation has +- infinity real roots!" + Environment.NewLine);
                }
            }
        }

        Main();
    }
}