[guimplen]

I think the text is geared towards people with some mathematical background who want to understand learning theory. Besides it is clearly stated that this chapter is a review (so its assumed that you learned or will learn these things elsewhere).

[throwaway81523]

Well I have some math background but that section is brisk and slow at the same time, as it were. Such as how it explains how to find inverses of 2x2 matrices.

This is older but is supposed to be good: https://www.deeplearningbook.org/