#include <library.h>

double sine(double x)
{ int n = 1, porm = 1;
  double sum = 0, fact = 1, powe = x;
  while (n < 22)
  { sum = sum + porm * powe / fact;
    fact = fact * (n+1) * (n+2);
    powe = powe * x * x;
    porm = - porm;
    n = n + 2; }
  return sum; }

void main()
{ const double pi = acos(-1.0);
  cout << sine(pi/2) << "   " << sin(pi/2) << "\n";
  cout << sine(pi/4) << "   " << sin(pi/4) << "\n";
  cout << sine(pi/3) << "   " << sin(pi/3) << "\n"; }