simple chain rule



hi toko

you may calc this with pdiff package .(written by Barton)

(%i16) load(pdiff);
(%o16)      /usr/share/maxima/5.9.3/share/contrib/pdiff/pdiff.lisp
(%i17) pdiff:on;
from cvs diff forms get differential forms package

(%i18) batch("cartan_init.bat");
......
(%i33) f_star([t],(x:t,y:t/%e,depends(f,[x,y]),d(f(x,y))));
                             - 1        - 1                 - 1
(%o33)       Dt f      (t, %e    t) + %e    Dt f      (t, %e    t)
                 (1, 0)                         (0, 1)

thanks

Gosei Furuya





2006/11/11, Tomek <toko at os.pl>:
>
> Hallo,
>
> I would like Maxima to do something like:
>
> s(t) := t / e
>
> Now I would like the following
>
> diff (f (t, s), t)
>
> to be resolved as
>
> df/dt + 1/e * df/fs
>
> How can I make it work ?
>
> Thanks,
> Tomek
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