When I solve the equations I obtained from the code in this question, I get a number of solutions. Most of them complex numbers, whereas the single real solution simply prints as r1 when first executing the code, as r2 next, and so on. So I gather that this is some root which Maxima or whoever is doing the solving cannot reduce to radicals.
So far, so good, but I'd still like to be able to get an idea of what that thing represents. Saving my solutions to a list of dictionaries, I've been able to isolate that value, but I can't seem to find any reasonable methods to obtain further details. In particular, r.n() tells me that it
TypeError: cannot evaluate symbolic expression numerically