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

namespace Simple_Iteration {
    class Program {
        public static double eps = 0.0001;

        public static double F(double x) {
            double retValue = Math.Sqrt((1 - x) - Math.Tan(x));
            return retValue;
        }

        public static double GetSolve(double leftRange, double rightRange, double lyambda) {
            double x1 = leftRange,
                   x2 = 0.0,
                   d = 0.0;
            do {
                x2 = x1 + lyambda * F(x1);
                d = Math.Abs(x2 - x1);
                x1 = x2;
            } while (d > eps);
            return x1;

        }

        static void Main(string[] args) {
            double leftRange = 0.0,
                   rightRange = 1.0,
                   lyambda = 0.00599,
                   x = 0;
            Console.WriteLine("Границы нахождения корня [{0},{1}]", leftRange, rightRange);
            x = GetSolve(leftRange, rightRange, lyambda);
            Console.WriteLine("x = {0:f5}", x);
            Console.WriteLine("Проверка верности найденного корня:\nF(x1) = {0:f2}", F(x));
            Console.ReadKey();
        }
    }
}