[naraht]

I don't think I sold *any* of the books in mathematics major back, but did so for many of the books outside my major. Up until my senior year, I was intending to go to Grad School and so kept them as idea sources for areas of concentration. My senior year I decided I had enough of school and decided to get a job in Computer Programming (which I had sort of kept as a minor)...

In the higher level mathematics courses (beyond Differential Equations) the use of specific textbooks tended to be spotty (the courses weren't necessarily offered two semesters in a row and different profs chose to use different text books.

The ultimate in "non-sellability" was the professor in General Topology (Grad level course) who decided that he wanted to use a book he owned printed in the 1920s as his primary textbook (and yes, this can be done in Mathematics) and tracked down the company who owned the copyright for the book. (The original publisher had been bought out a long time ago). While they weren't willing to print the book, they were willing to let the Professor make copies.

I still enjoy paging through my mathematics text books, but know I won't be able to get too deep in them unless I'm willing to sit down and do the proofs in them. (I'm talking things like Topology, Graph Theory and Projective Geometry).