#include <stdio.h>
#include <math.h>
double newton(double x0,double eps, int maxiter, int *ifail)
{
  double x, xlast, fun(), defun();
  int iter;
  printf("Start Value= %14.6f Stopping Rule=%15.8e\n",x0,eps);
  x=x0;
  for (iter=0; iter < maxiter; iter++){
    xlast=x;
    x-=fun(&x)/defun(&x);
    printf("Iteration No= %4d Iterate= %15.7f\n",iter,x);
    if(fabs(xlast-x)<eps) 
      return(x);
  }
  *ifail=1;
  return;
}