Hi Damiano,
> (%i1) T:matrix([3,45,6,7,8]);
>
> (%o1) [ 3 45 6 7 8 ]
> (%i2) t:matrix([0,3,48,54,61,69]);
> (%o2) [ 0 3 48 54 61 69 ]
> (%i3) algsys([5/N-sum(F*%
> E^(-F*t[1,i])*T[1,i],i,1,5)=0,5/F-sum(t[1,i],i,1,6)-sum(F*n*t[1,i]+%
> E^(-F*t[1,i])*T[1,i],i,1,5)=0],[N,F]);
>
> i got the follwing error :
>
> ALGSYS cannot solve - system too complicated.
Well, I don't know how difficult or easy it should be to solve it.
If you can accept a numerical solution, you can try using
mnewton (multivariate Newton method). Get mnewton.mac from:
http://cvs.sf.net/viewcvs.py/maxima/maxima/share/contrib/
Defining F1(N,F) := (left side of one equation),
F2(N,F) := (left side of other equation), and trying
some different starting points, I get the following:
(%i28) mnewton([F1(N,F),F2(N,F)],[N,F],[0.001,0.001]);
(%o28) [[N = 5.601022146947916, F = .0164121839939073]]
and checking the would-be solution --
(%i31) subst([N = 5.601022146947916, F = .0164121839939073], F1(N,F));
(%o31) - 3.48165940522449E-13
(%i32) subst([N = 5.601022146947916, F = .0164121839939073], F2(N,F));
(%o32) - 9.99200722162641E-16
Hope this helps,
Robert Dodier
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com