#include <iostream>
#include <cmath>
using namespace std;
double f(double x)
{
return (x-1)*(x-1)-5;
}
double findRoot(double (*f)(double), double a=2, double b=43, double eps=1e-6)
{
double t;
while(fabs(b-a)>=eps)
{
t =( b*f(a)-f(b)*a)/(f(a)-f(b));
if(f(a)*f(t)<0)
b=t;
else if(f(t)*f(b)<0)
a=t;
else return t;
}
return t;
}
int main()
{
double x = findRoot(f);
cout<<"x="<<t<<" f(x)="<<f(x)<<endl;
return 0;
}

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

namespace ConsoleApplication44
{
    class Class2
    {
        double epsilon = 0.001;

        private double f(double x)
        {
            return Math.Pow(x, 3) + 5 * x * x - 4 * x + 8;
        }
        public double Result(int count)
        {
            double a=-8;
            double b=0;
            double t=0;
            while (b - a > epsilon)
            {
                t =( b*f(a)-f(b)*a)/(f(a)-f(b));
                if(f(a)*f(t)<0)
                    b=t;
                else if(f(t)*f(b)<0)
                    a=t;
                else 
                    return t;
                count++;
            }
        }      

    }
}