Wikipedia can be really helpful when you are already at an advanced level in math - to quickly look up definitions. For learning the fundamentals, it is comple

Wikipedia can be really helpful when you are already at an advanced level in math - to quickly look up definitions. For learning the fundamentals, it is completely useless. Too many cross-references, which you ALL have to understand in math. https://proofwiki.org/wiki/Main_Page https://proofwiki.org/wiki/Main_Page Proofwiki keeps the proofs honest and should be readable like a textbook, as long as you look up the right things. Proofwiki will actually tell you which proofs you have to understand before the one you are currently looking at. I don't how complete it is, though. Its strictly about proofs, though. Actually calculating stuff is probably more important to you. The problem with "following a course in linear algebra" is that linear algebra is where math students learn reading and writing proofs, which takes practice - just like learning programming from a book vs. actually programming. In order to get anywhere here, you need to apply your knowledge.