var7

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace var7
{
    class Program
    {
        static void Main(string[] args)
        {
            double z1, z2, a, b;
            Console.Write("a = ");
            a = Convert.ToDouble(Console.ReadLine());

            z1 = Math.Pow(Math.Cos(3.0 * Math.PI / 8 - a / 4), 2) - Math.Pow(Math.Cos(11.0 * Math.PI / 8 + a / 4), 2);
            z2 = (Math.Sqrt(2) / 2) * Math.Sin(a / 2);
            Console.WriteLine("z1 = {0}\nz2 = {1}", z1, z2);

            Console.ReadKey();
        }
    }
}