Comment by jayro

We just released a comprehensive online course on Multivariable Calculus (https://mathacademy.com/courses/multivariable-calculus), and we also have a course on Mathematics for Machine Learning (https://mathacademy.com/courses/mathematics-for-machine-lear...) that covers just the matrix calculus you need in addition to just the linear algebra and statistics you need, etc. I'm a founder and would be happy to answer any questions you might have.