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 _4_28
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            double cos = Math.Cos(2);
            double sin = Math.Sin(2);
            double cot = cos / sin;
            MessageBox.Show(cot.ToString());
        }
    }
}
