>>14273390the problem i've seen at least in the US is that calc 1 introduces differentiation with a proof and limits. 90% of US students have never seen a proof or a limit in their life, and got through high school just doing basic algebra. calc 1 is consistently one of the most flunked classes in college if not THE most since it's a pre-req in every stem major.
basically upon getting to calc 1 students need to learn what a limit is and how to read a proof, and at least in my case it was expected that you knew this beforehand to begin the course. i took calculus in high school so i was familiar with it but a lot of my classmates had this problem
eventually during calc 1 they teach you the easy way of taking derivatives and all the identities. w
