function [s] = sinf(x)
   n = 10;
   if abs(x) >= 1.9
      s = x - sin(x);
   else
      t = x*x*x/6;
      s = t;
      for k = 1 : (n-1)
         t = -t*x*x/((2*k+2)*(2*k+3));
         s = s + t;
      end
   end
end