Не работает форма, в чем ошибка? - C#

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 Nyaaa
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
 
            double x;
 x =  double.Parse(textBox1.Text);
            if (x < -3)
            {
                double y = (Math.Pow(2 * x, 9) + 128);
                label1.Text = "" + y;
            }
            if (x > 6)
            {
                double y = (2 / 71 * Math.Pow(x, 4) - 2 * Math.Pow(x, 3) + 143);
                label1.Text = "" + y;
            }
            if ((x <= 6) && (x >= -3))
            {
                double y = (-14 * Math.Pow(x, 3) + 5 * Math.Pow(x, 2) + 2 * x);
                label1.Text = "" + y;
 
            }
        }
    }
}