# Calculus and Linear Algebra

While Ng's ML course spends valuable time covering the basics of matrices, I found it necessary to spend a little more time getting my bearings in math world. If you took advanced math in high school, you probably won't need this section.

## Jon Krohn's ML Foundations

Jon Krohn is a fantastic ML educator and he made his introductory math courses free to the public on YouTube. If, like me, you entered the CS field a little behind in math skills, you'll find his careful and patient style refreshing.

I just found myself watching these videos as needed. Here's the playlist for linear algebra (opens in a new tab), and here's the one for calculus (opens in a new tab).

## The Essence of Calculus by 3 Blue 1 Brown

Ready for a night at the symphony? That's how Grant Sanderson's videos feel. The first five (opens in a new tab) videos cover everything you'll need for our purposes.

At this point, any murky bits of Ng's explanation of gradient descent in linear regression should be cleared up, fully revealing the elegant, simple mechanism pinning together so much of ML.