Bisection Method

This is the solution for finding the roots of a function by Bisection Method in C++ Object Oriented Approach

#include <iostream>
#include <math.h>

using namespace std;

class Bisection
{
public:
    Bisection()
    {
        Error = 99;

    }
    void askFun();
    void askBrackets();
    double f(double x);
    void display();
    void findError();
    void findX0();
    void solve();
private:
    double a,b,c;
    double x0,x1,x2;
    double Error;
};

void Bisection::askFun()
{
    //can only perform for quadratic eqn. change for other equation
    cout.setf(ios::fixed,ios::floatfield);
    cout.precision(4);
    cout << "Enter a,b,c of ax^2+bx+c = 0: " ;
    cin >> a >> b >> c;
}

void Bisection::askBrackets()
{
    cout << "Enter two points: ";
    cin >> x1 >> x2;
}

double Bisection::f(double x)
{
    return a*x*x+b*x+c; // solves all equation of the form a*x*x+b*x+c;
}

void Bisection::findError()
{
    Error = fabs((x2-x1) / x2);
}
void Bisection::findX0()
{
    x0 = (x1+x2)/2;
}
void Bisection::solve()
{
    if(f(x1) * f(x2) < 0)
    {
        cout << "\nS.N.\tx1\tx2\tf(x1)\tf(x2)\tx0\tf(x0)\tError\n";
        while(Error>=0.00009)
        {
            findX0();
            findError();
            display();
            if(f(x1) * f(x0) < 0)
                x2 = x0;
            else
                x1 = x0;
        }

        cout << endl << endl << "The Root is : " << x0 << endl;
    }
    else
        cout << "There lies no root in between the given points" << endl;
}
void Bisection::display()
{
    static int i;
    cout << ++i << "\t" << x1 << "\t" << x2 << "\t" << f(x1) << "\t" << f(x2) << "\t" << x0 << 

    "\t" << f(x0) << "\t" << Error << endl;

}
int main()
{
    Bisection b1;
    b1.askFun();
    b1.askBrackets();
    b1.solve();
    return 0;
}