private void btnGradient_Click(object sender, EventArgs e)
        {
            if (egoldsGoogleTextBox1.Text == "" || egoldsGoogleTextBox2.Text == "" || egoldsGoogleTextBox3.Text == "")
            {
                MessageBox.Show("Пожалуйста введите значение во все поля!", "Ошибка!", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            else
            {
                Random rnd = new Random();
                int x = Convert.ToInt32(egoldsGoogleTextBox1.Text);

                double nach = Convert.ToDouble(egoldsGoogleTextBox2.Text);
                double end = Convert.ToDouble(egoldsGoogleTextBox3.Text);
                double razn = (end - nach) * 10;
                double integ = 785;

                if (nach > end)
                {
                    MessageBox.Show("Пожалуйста введите корректные значения диапазона!", "Ошибка!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
                else if (nach < 0)
                {
                    MessageBox.Show("Пожалуйста введите корректные значения диапазона!", "Ошибка!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
                else
                {
                    label3.Visible = true;
                    label9.Visible = true;
                    listBox1.Visible = true;
                    label6.Visible = true;
                    listBox2.Visible = true;
                    pictureBox2.Visible = true;
                    yt_Button2.Visible = true;
                    yt_Button3.Visible = true;
                    label11.Visible = true;
                    label12.Visible = true;


                    listBox1.Items.Clear();
                    listBox2.Items.Clear();


                    double chet = nach;

                    double[] mass = new double[1000];

                    mass[0] = nach;
                    listBox1.Items.Add(mass[0].ToString("F1"));

                    for (int i = 1; i < razn + 1; i++)
                    {
                        chet = chet + 0.1;
                        mass[i] = chet;
                        listBox1.Items.Add(mass[i].ToString("F1"));
                    }

                    if (egoldsGoogleTextBox8.Visible == true)
                    {
                        if (egoldsGoogleTextBox8.Text == "")
                        {
                            MessageBox.Show("Пожалуйста введите значения во все поля!", "Ошибка!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        }
                        else
                        {
                            integ = Convert.ToDouble(egoldsGoogleTextBox8.Text);
                        }
                    }

                    if (egoldsGoogleTextBox4.Visible == true | egoldsGoogleTextBox5.Visible == true)
                    {
                        if (egoldsGoogleTextBox4.Text == "" || egoldsGoogleTextBox5.Text == "" || egoldsGoogleTextBox6.Text == "" || egoldsGoogleTextBox7.Text == "")
                        {
                            MessageBox.Show("Пожалуйста введите значения во все поля!", "Ошибка!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        }
                        else
                        {
                            double x1 = Convert.ToDouble(egoldsGoogleTextBox4.Text);
                            double x2 = Convert.ToDouble(egoldsGoogleTextBox5.Text);
                            double c1 = Convert.ToDouble(egoldsGoogleTextBox6.Text);
                            double c2 = Convert.ToDouble(egoldsGoogleTextBox7.Text);


                            double rand = 0;
                            rand += mass[rnd.Next(0, (int)razn)];

                            double r1 = x1 + (x2 - x1) * rand;
                            double r2 = c1 + (c2 - c1) * rand;

                            label4.Text = ($"R1 = {x1} + ({x2} - {x1})*{rand.ToString("F1")}");
                            label5.Text = ($"R1 = {r1.ToString("F1")}");

                            label8.Text = ($"R2 = {c1} + ({c2} - {c1})*{rand.ToString("F1")}");
                            label7.Text = ($"R2 = {r2.ToString("F1")}");

                            label10.Text = ($"y = {integ}");

                            int h = 0;
                            int t = 0;

                            if (integ > r2)
                            {
                                for (int i = 0; i < x; i++)
                                {
                                    h++;
                                    t++;
                                    listBox2.Items.Add($"N1 = {h} | N2 = {t} | y = {integ}");
                                }
                                label2.Text = $"Значение интеграла больше чем R2 | {r2.ToString("F1")} <> {integ}";
                            }
                            else
                            {
                                for (int i = 0; i < x; i++)
                                {
                                    h++;
                                    listBox2.Items.Add($"N1 = {h} | y = {integ}");
                                }
                                label2.Text = $"Значение интеграла меньше чем R2 | {r2.ToString("F1")} <> {integ}";
                            }
                        }
                    }
                    else
                    {
                        double rand = 0;
                        rand += mass[rnd.Next(0, (int)razn)];

                        double r1 = 10 + (5 - 10) * rand;
                        double r2 = 0 + (210 - 0) * rand;

                        label4.Text = ($"R1 = 10 + (5 - 10)*{rand.ToString("F1")}");
                        label5.Text = ($"R1 = {r1.ToString("F1")}");

                        label8.Text = ($"R2 = 0 + (210 - 0)*{rand.ToString("F1")}");
                        label7.Text = ($"R2 = {r2.ToString("F1")}");

                        label10.Text = ($"y = {integ}");

                        int h = 0;
                        int t = 0;

                        if (integ > r2)
                        {
                            for (int i = 0; i < x; i++)
                            {
                                h++;
                                t++;
                                listBox2.Items.Add($"N1 = {h} | N2 = {t} | y = {integ}");
                            }
                            label2.Text = $"Значение интеграла больше чем R2 | {r2.ToString("F1")} <> {integ}";
                        }
                        else
                        {
                            for (int i = 0; i < x; i++)
                            {
                                h++;
                                listBox2.Items.Add($"N1 = {h} | y = {integ}");
                            }
                            label2.Text = $"Значение интеграла меньше чем R2 | {r2.ToString("F1")} <> {integ}";
                        }
                    }
                }
            }
        }

        private void yt_Button1_Click(object sender, EventArgs e)
        {
            if (cmbStyle.Visible == false)
            {
                cmbStyle.Visible = true;
            }
            else
            {
                cmbStyle.Visible = false;
            }
        }

        private void yt_Button2_Click(object sender, EventArgs e)
        {
            if (egoldsGoogleTextBox4.Visible == false)
            {
                egoldsGoogleTextBox4.Visible = true;
                egoldsGoogleTextBox5.Visible = true;
                egoldsGoogleTextBox6.Visible = true;
                egoldsGoogleTextBox7.Visible = true;
            }
            else
            {
                egoldsGoogleTextBox4.Visible = false;
                egoldsGoogleTextBox5.Visible = false;
                egoldsGoogleTextBox6.Visible = false;
                egoldsGoogleTextBox7.Visible = false;
            }
        }

        private void yt_Button3_Click(object sender, EventArgs e)
        {
            if (egoldsGoogleTextBox8.Visible == false)
            {
                egoldsGoogleTextBox8.Visible = true;
            }
            else
            {
                egoldsGoogleTextBox8.Visible = false;
            }
        }