---

using System;

class Program
{
    static double F(double x)
    {
        return x*x+5*x+6;
    }

    static void Main()
    {
        double a = 1;
        double b = 4;
        double e = 0.001;
        double c;

        do
        {
            c = b - F(b) * (b - a) / (F(b) - F(a));

            a = b;
            b = c;
        }
        while (Math.Abs(F(c)) > e);

        Console.WriteLine("Корень C: " + c);
        Console.WriteLine("f(c): " + F(c));
    }
}