Yes, UIUC offers very good online math courses: https://netmath.illinois.edu/college/math-415 https://netmath.illinois.edu/college/math-415. There is also a mor

Yes, UIUC offers very good online math courses: https://netmath.illinois.edu/college/math-415 https://netmath.illinois.edu/college/math-415. There is also a more pure/abstract version of that course available. If you don’t care about accreditation and are patient, sit down with Axler’s Linear Algebra Done Right and Hoffman & Kunze’s Linear Algebra, in that order. I would caution you against trying to learn linear algebra using a “take what you need” approach. A random walk approach to learning the material is faster than an accumulation approach, but it’s more brittle and prone to confusion. A lot of things which appear to be irrelevant or unnecessary for machine learning (computation or research) can be imperative for understanding or implementing much more complex concepts later on.