Does Calculus leave you a bit confused and unsure why certain important formulas are true. Why is the derivative of Sin(x) a Cos(x)? Why is the derivative of f(x) * m(x) equal to f(x) * m’(x) + f’(x) * m(x)? Multiplication, trigonometry and other mathematical concepts had a clear geometric representation but once derivatives enter the picture the geometry seems to become irrelevant. Sadly, most people never find out that geometry underlies all of the basic derivatives. Interestingly enough, for many people understanding calculus through geometry instead of limits happens to be a far simpler and more intuitive approach. Feel free to take a look at the book or the videos and judge for yourself.