simple derivative function question



Hello,
  I want to consider derivatives as functions.

How does maxima do this?

For instance,

(%i14) f(x):= diff(x^3,x);
                                             3
(%o14)                        f(x) := diff(x , x)
(%i15) f(2);

Non-variable 2nd argument to diff:
2
#0: f(x=2)
  -- an error.  To debug this try debugmode(true);

How does one define the derivative as a function, so one can compute
values, plots, etc?

TIA,
  -sen



-- 
  ---------------------------------------------------------------------------
  | Sheldon E. Newhouse            |    e-mail: sen1 at math.msu.edu           |
  | Mathematics Department         |       				   |
  | Michigan State University      | telephone: 517-355-9684                |
  | E. Lansing, MI 48824-1027 USA  |       FAX: 517-432-1562                |
  ---------------------------------------------------------------------------