We know that there are 3 levels of calculus. I want to know if there is a calculus 4 course. Some people say that differential equations is calculus 4 in disguise. What do you say?
To my understanding, Calculus 3 is Multivariable Calculus. Yes? Why do you think Calculus 1-3 is introductory material?
I've seen a few minutes of Calculus 3 on youtube by Professor Leonard. It does not look simple to me. The concept of vectors must be thoroughly understood to grasp this level of Calculus. Your thoughts?