I have recently dipped my toes into the topic of Machine Learning / Deep Learning and I would like to understand the underlying mathematical concepts.
I'm looking for an optimal way to learn the basics (mostly what can be found in a typical undergraduate math curriculum).
Going back to university would be the simplest choice but I don't have the time to do so. Another problem with it is that from my experience it is incomparably harder to understand compared to an online guide like this (note that this might only be the case in my country).
What choices do I have (getting certified is a bonus)?
Addendum: My biggest problem with a university was that it is hard to bridge the gap between what I learned in high school and the undergraduate topics. For example, it was hard to grok calculus back then so I chose to go to a teacher and after a few weeks with him, I was like "this is so simple I don't know why I had problems". Going to a math teacher would be the best option in terms of efficiency but a good teacher is more expensive than a university course and does not come with a degree.