//Elaborado por Leonardo Argüelles

using System;

​

public class Program

{

    public static void Main()

    {

            double x_inicial = 2, x_final = 9, paso = 0.001, y = 7.6, dy;

​

            for (double x = x_inicial; x <= x_final; x += paso)

            {

                dy = Math.Pow(x, 2) + 3 * x + 5;

                y = y + dy * paso;

            }

​

            Console.WriteLine("Función 1: \nCuando x vale 9 y es: " + Math.Round(y, 2)+"\n");

​

            double y2 = -5.6, k1, k2, k3, k4;

            x_inicial = 2; x_final = 12; paso = 0.001; dy = 0;

​

            for (double x = x_inicial; x < x_final; x += paso)

            {

                k1 = -Math.Sin(x) + 5 * y2 * Math.Cos(x);

                k2 = -Math.Sin(x + paso / 2) + 5 * y2 * Math.Cos(x + paso / 2) + k1 * paso / 2;

                k3 = -Math.Sin(x + paso / 2) + 5 * y2 * Math.Cos(x + paso / 2) + k2 * paso / 2;

                k4 = -Math.Sin(x + paso) + 5 * y2 * Math.Cos(x + paso) + k3 * paso / 2;

​

                y2 = y2 + (k1 + 2 * k2 + 2 * k3 + k4) * paso / 6;

            }

            Console.WriteLine("Función 2: \nCuando x vale 12 y es: " + Math.Round(y2, 2));

        }

    }

​

​