<p>In order to understand derivations for much of my aerodynamics course, I had to go back to my old calc III teacher to ask for another copy of her digital notes since I had accidentally lost the pdf files. Big time saver vs. rereading the book+redoing practice problems involving surface integrals and divergence theorem from scratch. Regardless, once I could work through the derivations myself, I understood the limitations of the closed form algebraic solutions much better. I substantiate this claim with my performance on the final exam; highest grade in the class ^_^</p>