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;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        double r, l, extr, x ;

        double f (double x)
        {
            return Math.Exp(x) - 2 * x - 3;
        }
        public Form1()
        {
            InitializeComponent();
        }

        public void button1_Click(object sender, EventArgs e)
        {
            chart1.ChartAreas[0].AxisY.ScaleView.Zoom(-100, 100);
            chart1.ChartAreas[0].CursorX.IsUserEnabled = true;
            chart1.ChartAreas[0].CursorX.IsUserSelectionEnabled = true;
            chart1.ChartAreas[0].AxisY.ScaleView.Zoomable = true;
            chart1.ChartAreas[0].AxisY.ScrollBar.IsPositionedInside = true;
            for (double x = l; x < r; x++)
            {
                chart1.Series[0].Points.AddXY(x, Math.Exp(x) - 2 * x - 3);

            }
            for (double x = l; x < r; x +=.1d)
            {
                dataGridView1.Rows.Add(Math.Round(x,1), Math.Round(f(x),1));
            }
        }

        public void numericUpDown1_ValueChanged(object sender, EventArgs e)
        {
             l = Convert.ToDouble(numericUpDown1.Value);

        }

        public void numericUpDown2_ValueChanged(object sender, EventArgs e)
        {
             r = Convert.ToDouble(numericUpDown2.Value);

        }

        public double Dfdx(double x)
        {
            return Math.Exp(x) - 2;
        }


        double ExtrSearch(double l, double r, double epsilon= 0.001)
        {
            double m = (l + r) / 2;
            if (r - l <= 2 * epsilon) return m;
            double dl = Dfdx(l);
            double dr = Dfdx(r);
            double dm = Dfdx(m);
            if (dl * dr > 0) throw new Exception("Экстремума на этом интервале нет.");
            if (dm * dl > 0) return ExtrSearch(m, r);
            else return ExtrSearch(l, m);

        }

        private void button4_Click(object sender, EventArgs e)
        {
            extr = ExtrSearch(l, r);
            label3.Text = $"{ Math.Round(extr, 4)}";
        }

        private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

        }

        public void label3_Click_1(object sender, EventArgs e)
        {

        }

        public void label5_Click(object sender, EventArgs e)
        {

        }


        private void button2_Click(object sender, EventArgs e)
        {
            this.Close();
        }


        public void Form1_Load(object sender, EventArgs e)
        {

        }

        private void chart1_Click(object sender, EventArgs e)
        {

        }

        private void button5_Click(object sender, EventArgs e)
        {
            dataGridView1.Rows.Clear();
            foreach (DataGridViewRow row in dataGridView1.Rows)
            {
                chart1.Series[0].Points.Clear();
            }

        }

        private void менюToolStripMenuItem_Click(object sender, EventArgs e)
        {

        }

        private void отчетToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Form2 form2 = new Form2(extr);
            form2.ShowDialog();
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void label2_Click(object sender, EventArgs e)
        {

        }

        private void label3_Click(object sender, EventArgs e)
        {

        }


    }
}