These systems and Sage's "solutions" exhibit some *serious* problems. See [there](https://groups.google.com/g/sage-support/c/gGssS_15jxE)...
Le mardi 2 janvier 2024 à 12:30:14 UTC+1, Emmanuel Charpentier a écrit : > FWIW, a working workaround this interesting Maxima quirk (bug ?) is to use > sympy, as demonstrated here > <https://sagecell.sagemath.org/?z=eJyNj8sKgzAQRfeC_yBunKRT6oN2l18RhDYZIWLRYjN_X2NiuyiFrnLvHHImWboJCoeMthBpomGNQlWldC1Up0ZIbqFezzQxAZ2lO14kpwm9e1sftol26tprDRqdV_He2N-OzGzM8N48o8gIMw-J9-rhTOMT5tEuNwDtwk5lpQkRNX9GIWJ8qKrqUiBsXxOYddaMU_-gQeUzD3fOxW85fcspyulf-QulymS5&lang=sage&interacts=eJyLjgUAARUAuQ==> > . > > HTH, > > Le mardi 28 novembre 2023 à 16:36:30 UTC+1, Fernando Q. Gouvea a écrit : > >> Yesterday I was demonstrating to my calculus class Sage's ability to >> implement the method of Lagrange multipliers. I used a standard example, >> putting the following code into SageMath Cell: >> >> var('x,y,l') >> f(x,y)=10*x^(1/3)*y^(2/3) >> g(x,y)=5*x-6*y >> fx=diff(f,x) >> fy=diff(f,y) >> gx=diff(g,x) >> gy=diff(g,y) >> solve((fx(x,y)==l*gx(x,y),fy(x,y)==l*gy(x,y),g(x,y)==120),(x,y,l)) >> >> That works beautifully. Then I decided to show off Sage's powers by >> making a little change: >> >> var('x,y,l') >> f(x,y)=10*x^(1/3)*y^(2/3) >> g(x,y)=5*x^2+6*y >> fx=diff(f,x) >> fy=diff(f,y) >> gx=diff(g,x) >> gy=diff(g,y) >> solve((fx(x,y)==l*gx(x,y),fy(x,y)==l*gy(x,y),g(x,y)==120),(x,y,l)) >> >> SageCell now gives me a spinning symbol ("I'm working") for a while, >> then seems to exit without any result. On my local installation (Sage >> 9.2 on Windows) it returns an empty list, []. >> >> What is curious is that the constraint equation 5x^2 + 6y=120 is easily >> solved for y... >> >> Questions: >> >> 1) Shouldn't SageCell output an empty list here? >> >> 2) Is this a known limitation of "solve"? >> >> Fernando >> >> PS: It seems that if I add "algorithm='sympy'" then solutions are found. >> >> -- >> ================================================================== >> Fernando Q. Gouvea >> Carter Professor of Mathematics >> Colby College >> Mayflower Hill 5836 >> Waterville, ME 04901 >> fqgo...@colby.edu http://www.colby.edu/~fqgouvea >> >> >> >> -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/633463b4-c2c9-4d8c-add0-1a691a16e948n%40googlegroups.com.
