Early methods of calculus-esque mathematics were all over the place and a thing, but it was just applied to very specific occasion and they never dug deeper and went on developing a formula for general cases as they didn't seem to care to explore it further

Thats just it, thats why it took us longer to "discover" calculus, though, humans already used early forms of integrals and early forms of limit-like differentiation of geometrical applications

>>16714818
You need to wait until Dumbledore sends you mail for Hogwarts to attend to, then you have to sneak into the forbidden part of the schools library