using System;

using System.Collections.Generic;

​

​

public class QuadraticEq

{

    private int a, b, c;

    private List<double> roots = new List<double>();

    //default

    public QuadraticEq()

    {

        a = 1;

        b = 2;

        c = 1;

    }

    public QuadraticEq(int pa, int pb, int pc)

    {

        a = pa;

        b = pb;

        c = pc;

    }

    public int Discriminant

    {

        get

        {

            return (b*b - 4*a*c); // not b^2....

        }

    }

    public double[] GetRealRoots()

    {

        if(this.Discriminant > 0)

        {

            Console.WriteLine("{0}x^2 + {1}x + {2} has 2 roots", a, b, c); 

            roots.Add( (-b + Math.Sqrt(this.Discriminant)) / (2*a));

            roots.Add( (-b - Math.Sqrt(this.Discriminant)) / (2*a));

        }

        else if (this.Discriminant == 0)

        {

            Console.WriteLine("{0}x^2 + {1}x + {2} has 1 roots", a, b, c); 

            roots.Add( -b / (2*a) );  // remember to put 2*a in ()

        }

        else

        {

            Console.WriteLine("{0}x^2 + {1}x + {2} has 0 roots", a, b, c);  

        }

        return roots.ToArray();

    }

    public override string ToString()

    {

        return a + "x^2 +" + b + "x +" + c;

    }

    public static void Main()

    {

        QuadraticEq q = new QuadraticEq(2,7,2);

        Console.WriteLine("d = {0}", q.Discriminant);

        double[] results = q.GetRealRoots();

        foreach (double x in results)

        Console.WriteLine(x);

        Console.WriteLine("Equation is {0}",q);

​

    }

}