It’s on my bucket list to read through these lectures and grok them. Maybe it will be a retirement project? While we are talking about this, I feel like I need to brush up on my math. Does anyone know what level of math is required to work through these?
A sibling comment mentions linear algebra. Vectors are introduced early on, and the chapter on tensor introduces matrices (eg second rank tensors). Multi variable calculus? I can't find where partial derivatives enter, but there's a chapter on vector calculus (to get ready for Maxwell). Really, it's all in there with no prior knowledge needed.
It's certainly a lot easier if you've seen the material before and read FLP as a second perspective. Hence why so many of the attendees were grad students and faculty. What it lacks as a teaching aide is the mind numbing exercises that all physics students do in their first year to practice using the mathematics. There's a reason the "University physics" books are doorstops.