/*  Approximate a solution to f(x)=0 using 5 iterations of Newton's
    method with an initial guess of x0.

    Note:  If you change f you must also change df below.  */

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

double answer[]={ 3.00000000000000e+00, 2.33333333333333e+00,
    2.23809523809524e+00, 2.23606889564336e+00, 2.23606797749998e+00 };

double f(double x){
    return x*x-5;
}
double df(double x){
    return 2*x;
} 
double g(double x){
    /* Please fill in this function */
}
int main(){
    printf("This is problem 3 on quiz 2.\n");
    int flag=0;
    double x=1;
    for(int n=0;n<5;n++){
        x=g(x);
        printf("n=%d x_n=%.14e ",n+1,x);
        if(fabs(x-answer[n])<1e-11) printf(" ...okay!\n");
        else printf(" ...wrong.\n"),flag++;
    }
    if(!flag){
        printf("Congratulations!  Your answer is correct!\n");
    } else {
        printf("Please try again.  Your answer is incorrect.\n");
    }
    return 0;
}