A small update on my issue:
I talked to my professor earlier today about this, and although he doesn't
seem like he really understands the issue of free software vs. nonfree
software (he didn't read the link that explains free software, and of course
assumed that I meant "free of cost" when we first started talking), he has
basically said that he is willing to see about other options. The only
suggestion I could come up with was for me to turn in my homework the
traditional way (on paper), or at least do that for the homework problems
that require Flash to submit the answer; although WebAssign does not work
with Gnash, its presence fools the site into thinking I have Flash installed
(and therefore lets me see the problems), so this will work out OK (and I
need to go to WebAssign to read the problems anyway; the numbers in the
problems are randomly changed on a per-person basis, so I can't just use the
book).
My professor asked if he could forward the E-mail I sent him to the math
department so he could ask them for ideas, to which I of course said "go
ahead". Time will tell if they'll be of any help.
My professor seems to mainly have two concerns: the first concern he is
having is that my turning in homework the more traditional way would mean
more work for him. To make this less than a burden, I have set my acceptance
threshold to submitting any answers which don't require Flash (i.e. the ones
that either are multiple-choice or use standard textboxes) so that he only
needs to check those that do require Flash. His second concern is fairness;
he has it set so that on WebAssign, we get to keep trying to submit answers
to problems until we get it right. I have said that I don't mind this slight
disadvantage (and that's true), but he was insistent that it needs to be fair
(i.e. my ability to get the points on the homework needs to be essentially
equal to those who use WebAssign on all of the problems).
When I was talking to him, the only solution I could think of was to give him
the answers to the problems on paper. Though it's not much different, I can
also use LibreOffice Math to enter the answer and then use LibreOffice Writer
to embed it into an ODT (if Microsoft Word can read ODT files with formulae
in them, since that is the program he would likely be using) or PDF file;
I'll mention that possibility to him as well.
Does anyone have any other ideas?