private void button5_Click(object sender, EventArgs e)
        {
            ClearForm(); // išvalomi programos duomenys
            PreparareForm(-8, 8, -300, 300);
             x1 = -33.5; // izoliacijos intervalo pradžia
            x2 = 6.7; // izoliacijos intervalo galas
            Fx = chart1.Series.Add("F(x)");
            Fx.ChartType = SeriesChartType.Line;
            double l = -10;
            for (int i = 0; i < 100000; i++)
            {
                Fx.Points.AddXY(l, F(l)); l = l + (2 * Math.PI) / 50;
            }
            Fx.BorderWidth = 3;

            X1X2 = chart1.Series.Add("Rėžiai");
            X1X2.MarkerStyle = MarkerStyle.Circle;
            X1X2.MarkerSize = 8;
            X1X2.ChartType = SeriesChartType.Point;
            X1X2.ChartType = SeriesChartType.Line;


            XMid = chart1.Series.Add("Tiksliausias taškas");
            XMid.MarkerStyle = MarkerStyle.Circle;
            X1X2.ChartType = SeriesChartType.Point;
            X1X2.ChartType = SeriesChartType.Line;
            XMid.MarkerSize = 8;

            timer3.Enabled = true;
            timer3.Interval = 500; // timer3 intervalas milisekundemis
            timer3.Start();

        }


        private void timer3_Tick(object sender, EventArgs e)
        {
            X1X2.Points.Clear();
            float dx = (float)(0.5);
            if ((x1 + dx) < x2)
            {
                X1X2.Points.AddXY(x1, 0);
                X1X2.Points.AddXY(x1 + dx, 0);
                if (Math.Sign(F(x1)) != Math.Sign(F(x1 + dx)))
                {

                    richTextBox1.AppendText("\n----------------------------------------------------------------");
                    richTextBox1.AppendText(String.Format("\nFunkcijos g(x) Intervalas kur yra šaknis : [{0}; {1}] ", x1, x1 + dx));

                    //paprastos iteracijos

                    //Alfa radimas
                    float alpha = 0;
                    alpha = (float)(DF(x1) * (-1.5));
                    int i1 = 0;
                    while (Math.Abs(F(x1)) > 0.001 && i1 < 1000)
                    {
                        X1X2.Points.Clear();
                        X1X2.Points.AddXY(x1, 0);
                        i1++;
                        x1 = (float)(x1 + (1.0 / alpha) * F(x1));
                    }
                    XMid.Points.AddXY(x1, 0);
                    X1X2.Points.Clear();
                    richTextBox1.AppendText(String.Format("\n Paprastos iteracijos metodas : [{0}] - iteracija {1}", x1, i1+1));
                    richTextBox1.AppendText(String.Format("\n F({0}) = {1}", x1, F(x1)));
                    richTextBox1.AppendText("\n----------------------------------------------------------------");
                }
                x1 = x1 + dx;
                richTextBox1.AppendText(String.Format("\n Ieškomas intervalas: [{0}; {1}] ", x1, x1 + dx));
                return;
            }
            timer3.Stop();

        }