#include <stdio.h>
#include <math.h>
/*
#define F  (x*x - 5*x + 6)
#define FP (2*x - 5)
*/
#define F  sin(x)
#define FP cos(x)

int main() {
  double x, xp;
  double delta = 0.01;

  x = 3;
  xp =  x - F/FP;

  printf("x: %f   x': %f\n", x, xp);

  while ( fabs( x - xp ) >= delta ) {
    x = xp;
    xp = x - F/FP;

    printf("x: %f   x': %f\n", x, xp);

  }

  printf("Approximate root: %f\n", xp);

  return 0;
}