richTextBox1.Clear();




            double x, y, z, A, B, h;
            A = Convert.ToDouble(textBox1.
                Text);
             B= Convert.ToDouble(textBox2.
                 Text);
            h = Convert.ToDouble(textBox3.
                Text);
            for (x = A; x <= B + 0.1 * h; x += h)
            {
                y = Math.Cos(1.5 * x) * Math.Log10(2.5 * x);

                z = (Math.Exp(1 / Math.Pow(x, 1 / 2))) * Math.Sin(x);



                richTextBox1.Text += "x = " + x.ToString("0.00")
                + " \t y(x) = " + y.ToString("0.00")
                + " \t z(x) = " + z.ToString("0.00") + Environment.NewLine;