From: Richard F. <fa...@gm...> - 2023-01-22 18:58:39
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. I found no error in maxima 5.45.1 using wxmaxima front end (which, however, refused to display the result in 2D because of its length.) Could it be that some of those items in orderless() had previously been set to values? Note also that solving for B10 is particularly trivial since B10 occurs only once, as given. This kind of error usually depends on some hidden dependency, like a sqrt(b) in the expression. Since sqrt(b)^2-b is not obviously zero if sqrt(b) is given a different and unrelated symbolic name in the rational function system, there is an opportunity for missing common factors and a cancellation. Thanks for reporting this. RJF On Sun, Jan 22, 2023 at 9:36 AM Andrii Sokolov <and...@gm...> wrote: > Dear all, > > Recently I was not able to use 'solve' for an elementary linear equation--- > if 'orderless' was called before. The commands are invoked are the > following > (sorry for a lengthy input): > > orderless(w1, w2, W1, W2, k1, k2, g, f1, f2, K)$ > > eq : -%i*W1*B10 = K * ((%i*g*f1^3)/((%i*w1-%i*W1+k1)*((-%i*w1)+%i*W1+k1) > > *((-w1*w2)+(w1+w2)*W1-W1^2 > > +(%i*w2-%i*W1)*k1 > > +(%i*w1-%i*W1+k1) > *k2)) > -(%i*g*f1*f2^2)/((%i*w1-%i*W1+k1)*(%i*w2-%i*W2+k2) > > *((-w1*w2)+(w1+w2)*W2-W2^2 > > +((-%i*w2)+%i*W2) > *k1 > +((-%i*w1) > +%i*W2+k1) > *k2)) > > +(%i*g^3*f1*f2^2)/(((-w1*w2)+(w1+w2)*W1-W1^2+(%i*w2-%i*W1)*k1 > +(%i*w1-%i*W1+k1)*k2) > > *((-w1*w2)+(w1+w2)*W2-W2^2+(%i*w2-%i*W2)*k1 > +(%i*w1-%i*W2+k1)*k2) > *((-w1*w2)+(w1+w2)*W2-W2^2 > +((-%i*w2)+%i*W2)*k1 > +((-%i*w1)+%i*W2+k1)*k2))) > > +(%i*g > *(((-w1*w2^2)+w2^2*W1+(2*w1*w2-2*w2*W1)*W2 > +((-w1)+W1)*W2^2 > +(%i*w2^2-2*%i*w2*W2+%i*W2^2)*k1 > +((-w1)+W1+%i*k1)*k2^2) > *f1 > +f1*f2^2*K)) > /((-w1^2*w2^2)+2*w1*w2^2*W1-w2^2*W1^2 > +(2*w1^2*w2-4*w1*w2*W1+2*w2*W1^2)*W2 > +((-w1^2)+2*w1*W1-W1^2)*W2^2 > +(2*%i*w1*w2^2-2*%i*w2^2*W1 > > +((-4*%i*w1*w2)+4*%i*w2*W1)*W2 > +(2*%i*w1-2*%i*W1)*W2^2) > *k1+(w2^2-2*w2*W2+W2^2)*k1^2 > > +((-w1^2)+2*w1*W1-W1^2+(2*%i*w1-2*%i*W1)*k1 > +k1^2) > *k2^2)$ > > solve(eq, B10); > > which spits out: > > PQUOTIENT: Quotient by a polynomial of higher degree (case 1) > > Also if the rhs includes '- %i*w2*B10-k2*B10' additionaly, it diagnoses > 'case 2a' in the same PQUOTINENT message. In both cases 'solve' provides > an answer if 'orderless' was not called. > > I played a bit removing different parts of the equation and it was unclear > for me what causes an error. > > Could that be a bug? Probably related to > https://sourceforge.net/p/maxima/bugs/3273/ > and the discussion > https://maxima-discuss.narkive.com/yE8zdESX/quotient-by-a-polynomial-of-higher-degree > > I use Maxima 5.46.0 with GCL 2.6.12 from the RHEL 8 repo. > > Regards, > Andrii > > > > _______________________________________________ > Maxima-discuss mailing list > Max...@li... > https://lists.sourceforge.net/lists/listinfo/maxima-discuss > |