Re: Why this cannot be solved
- To: mathgroup at smc.vnet.net
- Subject: [mg116248] Re: Why this cannot be solved
- From: olfa <olfa.mraihi at yahoo.fr>
- Date: Tue, 8 Feb 2011 05:06:40 -0500 (EST)
- References: <iie085$bpp$1@smc.vnet.net> <iig77c$rle$1@smc.vnet.net>
On 4 f=E9v, 07:43, "Sjoerd C. de Vries" <sjoerd.c.devr... at gmail.com> wrote: > I'm not sure what you're trying to do here, aP is a function name, not > a variable. You can't solve for that. Also aP == a is not an algebrai= c > equation as both aP and a are heads not variables. > > Cheers -- Sjoerd > > On Feb 3, 11:32 am, olfa <olfa.mra... at yahoo.fr> wrote: > > > > > Hi Mathematica community, > > System 1) > > Reduce[Max[e, s + a[i]] == Max[c, d + aP[iP]] && d == s - a[n] > > +Sum[a[j],{j,i,n}] && > > aP == a && iP == n, {aP, iP, d, c}, Reals] > > > this gives: > > Reduce::nsmet: This system cannot be solved with the methods available > > to Reduce. > > > System 2) > > Reduce[Max[e, s + a[i]] == Max[c, d + aP[iP]] && d == s - a[n] > > +Sum[a[j],{j,i,n}] , { d, c}, Reals] > > > this gives solutions. > > > the only difference between them is the variables aP and iP and their > > respective equations. > > What I didn't understand is why the first system cannot be solved > > although I have given values for iP and aP inside of it? > > > thank you.- Masquer le texte des messages pr=E9c=E9dents - > > - Afficher le texte des messages pr=E9c=E9dents - if aP == a is not an algebraic equation as both aP and a are heads not variableshere why this example works: Reduce[x + Sum[a[index], {index, k, n}] == xP + Sum[aP[index], {index, kP, n}] && aP == a, {aP, xP}, Backsubstitution -> True]? Thank you.