"Stavros Macrakis" <macrakis at alum.mit.edu> schrieb:
On 4/15/07, Wolfgang Lindner <LindnerW at t-online.de> wrote:
>> (%i1) f(x):=exp(x)-1/4*x*exp(x);
>> (%i2) solve(f(x)=0,x);
>> (%o2) [x=4,%e^x=0]
>> (%i3) diff(f(x),x) ; /* f prime */ ...
>> AFAIK it is not possible to abbrevitae diff(f(x),x) with f'(x).
>> I use fp(x) to name 'f prime' etc.
>> Is there any symbol left (backquote?) to name f'(x) and causing no problems later?
>> What is your recommended work around?
>As a general rule, Maxima does a much better job with mathematical *expressions* than
>with mathematical *functions* with names (like f).
>So the natural way to handle this sort of thing in Maxima is
>f: exp(x)-1/4*x*exp(x);
>solve(f,x)$
>solve(diff(f,x),x)
> etc.>>
Thank you for your interesting hints on Maxima's capabilities. In Germany we have a
'didactical tradition in math' to perfer *functions* (at least since Felix Klein), not
terms - but using CAS the situation seems be on other one.
Following your advice will there be an 'uncomfortable term evaluation'?
My students will (fequently) have to calculate function values, function tables etc.
So - as far as I know - I should have to write
(%i4) subst(x=4, f) /* instead of f(4) */
if f is an term. Or is there an better possibility?
If there would be an 'term evaluator' like
(%i4') f | x=4 /* term f evaluated for x =4 */
one would have a simpler and shorter 'functionlike' notation.
So I have to decide: function - maybe no good job
term - no usual evaluation a la f(x)
HTH
Wolfgang
Leichlingen/Germany