RE : How to assign a derivative of a function to anew function?
Subject: RE : How to assign a derivative of a function to anew function?
From: laurent couraud
Date: Fri, 9 May 2008 20:12:21 +0200
> -----Message d'origine-----
> De?: maxima-bounces at math.utexas.edu [mailto:maxima-bounces at math.utexas.edu] De la part de
> Jaime Villate
> Envoy??: vendredi 9 mai 2008 18:00
> ??: Philippe Boeraeve
> Cc?: maxima at math.utexas.edu
> Objet?: Re: [Maxima] How to assign a derivative of a function to anew function?
>
> On Fri, 2008-05-09 at 12:01 +0200, Philippe Boeraeve wrote:
> > am trying to assign a derivative to a new function, in order to know
> > the value of the derivative of the function at one point.
>
> Besides the two methods that others have pointed out, there is a third
> method:
>
> (%i2) define(y(x), a*x^3+b*x^2+c*x+d)$
>
> (%i3) define(dy(x), diff(y(x),x))$
>
> Regards,
> Jaime Villate
>
You can do also:
(%i1) dy(xx):=at(diff(y(x),x),x=xx);
Laurent.