A formula for path length of a function (above)
I would call this somewhere between ragebait and "could've been smth useful".
For an elementary function like f(x) = x, this works btw. You only have to do one illegal thing, i.e lim h->0 h = dh. That gives you an exact formula for path length. For other functions, I couldn't figure out how to write lim h->0 in the form of dh. If I could (wrongly but still) I believe this would be a valid formula . Mathematically satanic, but works.
