Le lundi 17 novembre 2014 17:32:27 UTC+1, Chris Seberino a écrit : > > If you ask Sage to do something it can't, like solve a quintic polynomial > equation, it will spit the question back at you. > > If Sage did that I'd be fine. However, Sage spit back the empty set which > is the WRONG answer and far different yes? >
That weakness of sage's (maxima's, indeed) is well known. In maxima, an alternative solver (%solve, a. k. a. to_poly_solve) is available, that sage can use through the to_poly_solve option of sage's solve : sage: solve(5^( x -1) == (1/25)^(2*x), x, to_poly_solve=True) [x == (2*I*pi*z54 + log(5))/log(3125)] which gives you also the set of complex solutions (log is multivalued in the complex plane...). Sage seems to have trouble finding that log(3125)=log(5^5)=5*log(5), which it can easily check. So substitute it by hand to get an expression easier to handle. HTH, -- Emmanuel Charpentier On Sunday, November 16, 2014 12:54:20 PM UTC-6, RRogers wrote: > > Apparently the default solver doesn't do logarithms. > For the default try: > solve(log(5^( x -1)) == log((0.04)^(2*x)), x) > > [x == 8104022*log(5)/(8104022*log(5) + 52171681)] > > > > > -- 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 post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
