Numerical Method

nm_hw7.c

#include <stdio.h>
#include <math.h>

double f (double x)
{
    return x*x*x - 2 *x + 2;
}

double df(double x)
{
    return 3*x*x - 2;
}

double bisection(double a, double b)
{   
    double fa = f(a);
    double fb = f(b);
    double m;

    
    if (fa * fb > 0)
    {
        printf("Invalid starting point.\n");
        return 0.0;
    }
    

    int count = 0, MaxCount = 50;
    while (count++ < 50)
    {
        m = (a + b)/2.0;
        double fm = f(m);
    
        if (fabs(fm) < 1e-7)
        {
            return m;
        }
    
        if (fa * fm < 0)
        {
            b = m;
            fb = fm;
        }
        else 
        {
            a = m;
            fa = fm;
        }
    
        printf("%lf \t %lf\n", m, fm);    
    }
    
    return m;
}

double newton(double x)
{
    double fx = f(x);
    double dfx = df(x);
    double nx = x;
    
    do
    {
        x = nx;
        fx = f(x);
        dfx = df(x);
        
        printf("%lf \t %lf \n", x, fx);    
        nx = x - fx/dfx;
    }
    while (fabs(nx-x) > 1e-7);
    
    
    return x;
}

int main()
{
    printf("Hello, World!\n");
    
    double a, b;
    scanf("%lf %lf", &a, &b);
    double p = bisection(a, b);
    printf("Soultion: %lf\n", p);
    
    scanf("%lf", &a);
    double q = newton(a);
    printf("Solution :%lf\n", q);
    
    return 0;
}