NewtonRaphson.cpp

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

#define f(x) x *x - 3 * x + 2

#define g(x) 2 * x - 3

using namespace std;

int main()
{
    float x0, x1, f0, f1, g0, e;
    int step = 1, N;
    cout << setprecision(6) << fixed;

    cout << "Enter initial guess: ";
    cin >> x0;
    cout << "Enter tolerable error: ";
    cin >> e;
    cout << "Enter maximum iteration: ";
    cin >> N;

    cout << endl
         << "*********************" << endl;
    cout << "Newton Raphson Method" << endl;
    cout << "*********************" << endl;
    do
    {
        g0 = g(x0);
        f0 = f(x0);
        if (g0 == 0.0)
        {
            cout << "Mathematical Error.";
            exit(0);
        }

        x1 = x0 - f0 / g0;

        cout << "Iteration-" << step << ":\t x = " << setw(10) << x1 << " and f(x) = " << setw(10) << f(x1) << endl;
        x0 = x1;
        step = step + 1;
        f1 = f(x1);

    } while (fabs(f1) > e);

    cout << endl
         << "Root is: " << x1;
    return 0;
}