Me too. While I recall Calculus class, I’ve been paid to operate at the algebra level for years. I think this walkthrough is a retread of differential equations, in particular the kind that attempt to approximate the result of the function as it approaches the limit of a point. I get lost at the bits involving dimensionality. I think it’s evident but it’s been years since I’ve read mathematics at this level.

It took me a moment to realize you were using "Algebra" in a pejorative sense to mean a level of mathematics beneath Calculus, rather than as "The study of composable operators on quantitative spaces." Algebra is a very deep subject, no less advanced than Analysis (The branch of mathematics that includes Calculus).

A lot of people say "algebra" when they mean "arithmetic"!

Definitely one of my mathematical peeves. Right up there with people using "exponential" to say "a lot".

That's a tad worse than the related use of "exponential" for phenomena best described as geometric!