[bntyhntr]

My AP calc teacher was big into Leithold, specifically TC7 (https://www.amazon.com/Calculus-7-Louis-Leithold/dp/06734691...) when I had him. Claimed Stewart was useless, but he had a lot of strong opinions. I don't really have anything to say except that I have this feeling that I'm supposed to preach the gospel of TC7 anytime it comes up, so may as well :). Haven't touched calc in 10 years but sometimes still find myself trying to remember the chain rule (usually when miserable on a run)

[marcosdumay]

> but sometimes still find myself trying to remember the chain rule

There's an algebra of differentials that was formalized quite late (I think at the 19th century) but accepts all of the operations you can use for scalars. The chain rule is just fraction simplification.

[klyrs]

This paper is an old favorite of mine. It shows how to transform a program that computes the value of a multivariate function into a program that computes that value and all of its first derivatives. The resulting program requires at most 7x more instructions as the original. Spoiler: it's just the rules of differentiation, and the constant 7 comes from the quotient rule.

https://courses.cs.washington.edu/courses/cse446/18wi/slides...