simple derivative function question



hi

(%i9) f(_x):=block([t],subst([t=_x],diff(t^3,t)))$
(%i10) f(9);
(%o10)                                243

Gosei Furuya


2007/1/17, sen1 at math.msu.edu <sen1 at math.msu.edu>:
>
> 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                |
>
>   ---------------------------------------------------------------------------
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima
>