atan_recursion.cs

using System;

namespace lab1
{
    class Program
    {
        public static double power(double x, double n)
        {
            if (n == 0)
            {
                return 1;
            }
            else
            {
                return x * power(x, n - 1);
            }
        }

        public static double arctan(double x, double n)
        {
            if (n == 0)
            {
                return x;
            }
            else
            {
                return (power(-1, n) / (2 * n + 1) * power(x, 2 * n + 1)) + arctan(x, n - 1);
            }
        }
        static void Main(string[] args)
        {
            //double x, n, result, result1;

            //Console.WriteLine("please input x for arctan(x)+arctan(1/x), e.g. '2'. x must be integer number.");
            //x = double.Parse(Console.ReadLine());
            //Console.WriteLine("please input n to define calculation precision, number should be between 1 and 10");
            //n = double.Parse(Console.ReadLine());
            //result = arctan(x, n) + arctan(1 / x, n);

            //Console.WriteLine("arctan(x)+arctan(1/x) equals to " + result);
            //Console.WriteLine("arctan(x)+arctan(1/x) via embded function Math.Atan() equals to " + Math.Atan(x) + Math.Atan(1 / x));


            Console.WriteLine(arctan(0.2, 10));
            Console.WriteLine(Math.Atan(0.2));
            Console.ReadLine();
        }
    }
}