# Multi-Variable Calculus Complete

I finished multi-variable calculus on December 19th!

And like I said in my frequency and trajectory shift post, I am more focused now on completing the Physics GRE than maintaining that study timeline I had set out before… which I think I should adjust now.

I was having some trouble with the later chapters on Stokes Theorem, that really stemmed from my not understanding exactly how to calculate a unit normal vector (in 3D or curved 2D flux problems). I noticed that a majority of the practice problems would use heuristics or visual inspection to quickly arrive at the unit normal vectors, but I was lacking a good empirical mental image of what I was looking for. Luckily we have the helpful folks at Khan Academy! I will certainly write a post on them. The visuals that KA give are unparalleled. I wish I had begun making them a part of my study-learning routine earlier on. I will use them for DiffEQ.