Looking for Linear Algebra FREE course supplements (book and other)

Question

I am well aware that the tag "free" limits the search quite a bit, but I'm having some issue finding free resources myself so I thought I might extend the question to this community to see what you all might think up.

Specifically, I am looking for some free material to help me understand my linear algebra course better as I am unable to meet with my professor due to a massively busy schedule and my current book is hardly any help. The book we use is offered by UCDavis and I find it quite lacking in the example department.

Anything helps! Thanks everyone.

Answer 1

Linear Algebra by Jim Hefferon has been mentioned by Vikram in the comments, but I'd like to promote it to a full answer. This is a first-semester linear algebra textbook made available as a free PDF file (see the previous link) and as a relatively inexpensive paperback (see Google Books). Hefferon's Linear Algebra, now in its fourth edition, won the 2020 Daniel Solow Author's Award from the Mathematical Association of America; here one can read their reasons for the award, of which I quote an excerpt:

The nomination packet for Dr. Hefferon’s work spoke directly to how Linear Algebra works extraordinarily well for students. Not every student will have the same interests or abilities, but all can be encouraged and supported as they explore the parts of the subject that they can grasp and build on. As recent research has shown, active learning is demonstrably more effective than traditional lecture, and the book’s approach helps teachers to get students involved. This is especially true of the application sections that are highlighted in [a previously cited] review, as they give plenty of opportunity to have students put recently learned theory into context.

[…]

The clear writing style, tremendous variety of exercises, amenability to use with active learning strategies, and the careful attention to detail in preparation mean that the text is exceptionally adaptable.