Задача по языку С#

Помогите найти ошибку.Нужно написать в С# В WindowsForms
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 WindowsFormsApp6
{
public partial class Form1 : Form
{
private object textBox;
public Form1()
{
InitializeComponent();
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
textBox1.Text = "-15.246";
}
private void textBox2_TextChanged(object sender, EventArgs e)
{
textBox2.Text = "4.642 * Math.Pow(10,-2)";
}
private void textBox3_TextChanged(object sender, EventArgs e)
{
textBox3.Text = "20.001 * Math.Pow(10,2)";
}
private void Form1_Load(object sender, EventArgs e)
{
textBox4.Text = "Конт.раб №1 Ст.гр.Тяпкова И.С.ИБ261001";
}
private void button1_Click(object sender, EventArgs e)
{
double x = double.Parse(textBox1.Text);
textBox4.Text += Environment.NewLine +
"X = " + x.ToString();
double y = NewMethod();
textBox4.Text += Environment.NewLine +
"Y = " + y.ToString();
double z = double.Parse(textBox3.Text);
textBox4.Text += Environment.NewLine +
"Z = " + z.ToString();
double с = Math.Log(Math.Pow(y, -Math.Sqrt(Math.Abs(x)) * Math.Log(x - y / 2)));
double b = Math.Sin(Math.Atan(z)) * Math.Sin(Math.Atan(z));
double a = с + b;
textBox4.Text += Environment.NewLine +
"Результат A = " + a.ToString();
}
private double NewMethod()
{
return double.Parse(textBox2.Text);
}
}
}