lab.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;

namespace Lab1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            chart1.Series[0].Color = Color.Red;
        }

        private void выходToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Close();
        }


        private void Input(object sender, EventArgs e)
        {
            double a = Convert.ToDouble(textBox1.Text);
            double b = Convert.ToDouble(textBox2.Text);
            if ((sender as ToolStripMenuItem).Text.Equals("Построить график"))
            {
                MakeChart(a, b);
                return;
            }
            double eps = Convert.ToDouble(textBox3.Text);
            if (!Check(a, b))
            {
                MessageBox.Show("На задаенном интервале нет корней", "Ошибка");
                return;
            }
            if ((sender as ToolStripMenuItem).Text.Equals("Метод А")) A(a, b, eps);
            if ((sender as ToolStripMenuItem).Text.Equals("Метод Б2")) B2(a, b, eps);
        }

        private void MakeChart(double a, double b)
        {
            double dx = 0.01;
            chart1.Series[0].Points.Clear();
            for (double x = a; x <= b; x += dx)
                chart1.Series[0].Points.AddXY(x, F(x));
        }
        private double F(double x)
        {
            return 3 * x - Math.Cos(x) - 1;
        }
        private void A(double a, double b, double eps)
        {
            double c;
            int i = 0;
            do
            {
                c = (a + b) / 2;
                if (F(a) * F(c) < 0) b = c;
                else a = c;
                i++;
            } while (Math.Abs(F(c)) > eps);
            toolStripStatusLabel1.Text = "Метод : A";
            toolStripStatusLabel2.Text = "Кол-во итераций : " + i;
            toolStripStatusLabel3.Text = "Корень : " + c;
        }

        private bool Check(double a, double b)
        {
            return F(a) * F(b) < 0;
        }
        private double D1(double x, double eps)
        {
            return (F(x + eps) - F(x)) / eps;
        }
        private double D2(double x, double eps)
        {
            return (D1(x + eps, eps) - D1(x, eps)) / eps;
        }
        private void B2(double a, double b, double eps)
        {
            double x = (a + b) / 2;
            double x1, x2, t;
            x1 = x2 = 0;
            int i = 0;
            do
            {
                x2 = x1;
                x1 = x;
                if (F(a) * D2(a, eps) < 0) x = (b * F(x) - x * F(b)) / (F(x) - F(b));
                if (F(b) * D2(b, eps) < 0) x = (a * F(x) - x * F(a)) / (F(x) - F(a));
                t = (Math.Pow(x - x1, 2)) / (Math.Abs(2 * x1 - x - x2));
                i++;
            } while (t > eps);
            toolStripStatusLabel1.Text = "Метод : Б2";
            toolStripStatusLabel2.Text = "Кол-во итераций : " + i;
            toolStripStatusLabel3.Text = "Корень : " + x;

        }

    }
}