It's helpful to me to report bugs and weaknesses in %solve to the Maxima bug list--I maintain my own bug list, but it's easier for me if
the bugs are reported to the Maxima list. You can assign the task to me.
Some requests (such as only return real solutions in a given interval), I'm unlikely to do (because I simply do not know how to do them in a
way that would be satisfactory to me). But report them anyway--maybe it will help somebody else write the ultimate solve function.
--Barton
________________________________
From: maxima-bounces at math.utexas.edu [maxima-bounces at math.utexas.edu] on behalf of Stavros Macrakis [macrakis at alum.mit.edu]
Sent: Monday, October 29, 2012 16:17
To: Daniel Dalton; Barton Willis
Cc: maxima
Subject: Re: [Maxima] A variety of maxima queries
On Sun, Oct 28, 2012 at 12:59 AM, Daniel Dalton <daniel.dalton47 at gmail.com<mailto:daniel.dalton47 at gmail.com>> wrote:
...attempt to solve the resultant
equation with %solve:
%solve(sec(x/2)^2/2+cos(x/2)/2=0,x);
Nonalgebraic argument given to 'to_poly'
unable to solve
This is a bug in %solve. %solve appears to know about sec in some cases, but not others:
%solve(sec(x)=1,x) => OK
%solve(sec(x)=sin(x),x) => unable to solve
%solve(trigsimp(sec(x)=sin(x)),x) => OK
The workaround is to apply trigsimp to the equation first to convert sec/cot/csc/tan/etc. to combinations of sin/cos.
-s