I was recently working with my students on matrices and basic row operations. It dawned on me it has been quite a while since I’ve done anything with Linear Algebra outside of basic row operations. After a little searching I found a few sites offering free textbooks. I picked out a book from a site called Book Boon. They offer a enough titles to keep me going for quite a while. I’m currently halfway through Linear Algebra I, by Kenneth Kuttler. I’m really enjoying the interaction between theoretical and numerical application.
The site is http://bookboon.com. All that is required is a valid email address. I haven’t been bombarded with spam from the site, just a periodic newsletter suggesting other books based on my downloads.