using System;

public class Program

{

    public static void Main()

    {

        double yVVJ, k1VVJ, k2VVJ, k3VVJ, k4VVJ;            

        double xVVJ = 0, pasoVVJ = 0.0001;            

        yVVJ = 0;            

        while (xVVJ < 2.2)            

        {                

            k1VVJ = 1/(1 + xVVJ * xVVJ)-2 * (yVVJ * yVVJ);   

            k2VVJ = 1/(1 + (xVVJ + 0.5 * pasoVVJ) * (xVVJ + 0.5 * pasoVVJ)) -2 * ((yVVJ + .5 * k1VVJ * pasoVVJ) * (yVVJ + .5 * k1VVJ * pasoVVJ));                

            k3VVJ = 1/(1 + (xVVJ + 0.5 * pasoVVJ) * (xVVJ + 0.5 * pasoVVJ)) -2 * ((yVVJ + .5 * k2VVJ * pasoVVJ) * (yVVJ + .5 * k2VVJ * pasoVVJ));             

            k4VVJ = 1/(1 + (xVVJ + pasoVVJ) * (xVVJ + pasoVVJ)) -2 * ((yVVJ + k3VVJ * pasoVVJ) * (yVVJ + k3VVJ * pasoVVJ));                  

            yVVJ = yVVJ + (k1VVJ + 2 * k2VVJ + 2 * k3VVJ + k4VVJ) * pasoVVJ / 6;                

            xVVJ = xVVJ + pasoVVJ;                       

        }            

        Console.WriteLine("El valor de y cuando x es " + xVVJ + " es " + yVVJ);            

        Console.ReadLine();        

    }    

}