You don't need Lambert W to get a *numerical* solution! It's just that
Maxima's solve function doesn't solve numerically....
On 2/1/08, Paul Smith <phhs80 at gmail.com> wrote:
> On Feb 1, 2008 12:00 PM, Chris Sangwin <sangwinc at for.mat.bham.ac.uk> wrote:
> > You might be interested in looking up the mathematical background to the
> > "Lambert W function".
> >
> > http://www.cs.uwaterloo.ca/research/tr/1993/03/W.pdf
> >
> > I don't know of a Maxima implementaion of this (very useful) special
> > function.
>
> Thanks, Chris. Matbe Maple has it implemented, as
>
> > f := x -> exp(-x)*x-0.05;
> f := x -> exp(-x) x - 0.05
>
> > solve(f(x),x);
> 0.05270598355, 4.499755289
>
> Paul
>
>
> > On Fri, 1 Feb 2008, Paul Smith wrote:
> >
> > > On Feb 1, 2008 11:31 AM, Paul Smith <phhs80 at gmail.com> wrote:
> > >> Is there some trick to have Maxima solving the following equation:
> > >>
> > >> f(x):=x*exp(-x)-0.05;
> > >> solve(f(x),x);
> > >>
> > >> ?
> > >
> > > Well, with plot2d I identified the localization of the roots and then
> > > I got the value of them with:
> > >
> > > find_root(f(x),x,2,5);
> > > find_root(f(x),x,0,2);
> > >
> > > Paul
> > > _______________________________________________
> > > Maxima mailing list
> > > Maxima at math.utexas.edu
> > > http://www.math.utexas.edu/mailman/listinfo/maxima
> > >
> >
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima
>
--
Sent from Gmail for mobile | mobile.google.com