double cos(double radians)
{
  double result = 0;
  double sign = 0;
  double x2n = 0;
  double factorial = 0;
  int n, count;

  for (n = 0; n < 10; n ++)
    {
      sign = 1.0;
      for (count = 0; count < n; count ++)
     sign *= (double) -1;
     x2n = 1.0;
      for (count = 0; count < (2 * n); count ++)
      x2n *= radians;
      factorial = 1.0;
      for (count = (2 * n); count > 0; count --)
      factorial *= (double) count;
      result += (sign * (x2n / factorial));
    }
  return (result);
}