using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MetodNewton
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Решение уравнения 2x^4-24x^2-x+8 методом Ньютона.");
            Console.WriteLine();
            double[] cor = new double[] { 0.1, 0.01, 0.001 };
            double[] a = new double[] { -4, -1, 0.1, 3.2 };
            double[] b = new double[] { -3, -0.1, 1, 4 };
            double x = 0;
            double x1;
            double max;
            double min;
            for (int c = 0; c < 3; c++)
            {
                Console.WriteLine("Значения корней при точности {0}:", cor[c]);
                int k = 0;
                for (int n = 0; n < 4; n++)
                {

                    double ak = a[k];
                    double bk = b[k];
                    int iter = 1;
                    max = Math.Max(Math.Abs(Functoin2(ak)), Math.Abs(Functoin2(bk)));
                    min = Math.Min(Math.Abs(Functoin1(ak)), Math.Abs(Functoin1(bk)));
                    if ((Functoin(ak) > 0 && Functoin2(ak) > 0) || (Functoin(ak) < 0 && Functoin2(ak) < 0))
                        x = ak;
                    else
                        if (((Functoin(bk) > 0) && (Functoin2(bk) > 0)) || (Functoin(bk) < 0 && Functoin2(bk) < 0))
                            x = bk;
                    x1 = x - Functoin(x) / Functoin1(x);
                    {
                        while (Math.Abs(x1 - x) >= Math.Sqrt((2 * min * cor[c]) / max))
                        {
                            x = x1;
                            x1 = x1 - Functoin(x1) / Functoin1(x1);
                            iter++;
                        }
                        Console.WriteLine("Корень х{0} равен {1}. Количество итераций: {2}", n + 1, x1, iter);
                    }
                    k++;
                }
                Console.WriteLine();
            }
            Console.ReadLine();
        }
        public static double Functoin(double x)
        {
            double an = 2 * Math.Pow(x, 4) - 24 * Math.Pow(x, 2) - x + 8;
            return an;
        }
        public static double Functoin1(double x)
        {
            double an = 8 * Math.Pow(x, 3) - 48 * x - 1;
            return an;
        }
        public static double Functoin2(double x)
        {
            double an = 24 * Math.Pow(x, 2) - 48;
            return an;
        }
    }
}