Convert formula to C# Windows Form code?

Question

C++ / C#

Good day.
It is necessary to convert the formula into code for windows form

My code:

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 _432432432432432432
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }

        private void textBox2_TextChanged(object sender, EventArgs e)
        {

        }

        private void textBox3_TextChanged(object sender, EventArgs e)
        {

        }

        private void textBox4_TextChanged(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            // Получение исходных данных из TextBox
            double x = Convert.ToDouble(textBox2.Text);
            double y = Convert.ToDouble(textBox1.Text);
            double z = Convert.ToDouble(textBox3.Text);
            // Ввод исходных данных в окно результатов
            textBox4.Text = "Результаты работы программы " +
            "ст. студента " +
            Environment.NewLine;
            textBox4.Text += "При X = " + textBox2.Text +
            Environment.NewLine;
            textBox4.Text += "При Y = " + textBox1.Text +
            Environment.NewLine;
            textBox4.Text += "При Z = " + textBox3.Text +
            Environment.NewLine;
            // Вычисление выражения
            double u;
            if ((z - x) == 0)
                u = y * Math.Sin(x) * Math.Sin(x) + z;
            else
            if ((z - x) < 0)
                u = y * Math.Exp(Math.Sin(x)) - z;
            else
                u = y * Math.Sin(Math.Sin(x)) + z;
            // Вывод результата
            textBox4.Text += "U = " + u.ToString() +
            Environment.NewLine;
        }

        private void button2_Click(object sender, EventArgs e)
        {

        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void label2_Click(object sender, EventArgs e)
        {

        }

        private void label3_Click(object sender, EventArgs e)
        {

        }
    }
}