#include <iostream>
#include <iomanip>
#include <math.h>
using namespace std;

int main()
{
  double x = 1.;
  double (*pf)(double);
  pf = &sin;
  double y = (*pf)(x);
  cout << " sin(x) mit Zeiger " << y << endl;

  y = sin(x);
  cout << " sin(x) ohne Zeiger " << y <<endl;
  return 0;
}