jim hardy said:
@ yungman:
""Hey Jim, I am opposite, I find vector calculus easier than ODE. ..""
your revisiting high math in later years is an inspiration to me. maybe there's some hope...
my school used practical texts for calculus and diff-eq, chapters alternated theory and applications. so we got practice at real world problems in the math building too...
i'd like to try vector calc again. after years rubbing elbows with reactor physics types i began to appreciate the 3-dimensional significance of del, so maybe now i could make some sense of those awful equations. In his "Mathematician's Apology", British mathematiician G H Hardy expressed a sentiment that students who simply cannot grasp pure math can still make practical societal contributions, which was quite a relief to me.
a plodder,,
old jim
To me, as much as I keep pushing for math, I don't think most engineer use it in real life. It's really only important when you are in school. Blame it on those EM books that all explain the theories using calculus, if it is not because of that, you don't use it much. I just found through the years when I tried to study something, calculus always got in the way and it's so frustrating. That's the reason I said to myself for once, get over it.
ODE was really a shocker to me. It's has more to do with the way of thinking. Took me a long time to bend my mind to accept the way to get the solution of a differential equation and using numerical solution like series. I remember during the semester, the instructor was really like a private tutor for me. Every night I email to him and he answer me in detail. He must be spending average 45 minutes just for me through my struggle with ODE.
Regarding to multi-variables, You should look into Vector Calculus book. I have a lot of normal calculus book that cover the first three semester calculus. They are all very weak towards the end where you get into line integrals, Divergence and Stoke's theorem. The only one that is good enough to explain the subject is book by Howard Anton.
I don't mean to advice you as you are a respectable contributor here in my book. Maybe it's not you, it's the books. I have 4 or 5 and they are so bad. Maybe because it's the end of the book, even in class, they usually rush the last part at the end. The only book I think explain this good is this one:
https://www.amazon.com/Calculus-Multivariable-Howard-Anton/dp/0471482374/ref=sr_1_1?ie=UTF8&qid=1324513597&sr=8-1
Even I studied this book, when I looked back at the other few, I still don't think they make sense! That's how bad the others are.
Another free online notes are by Paul Dawkins:
http://tutorial.math.lamar.edu/Classes/CalcIII/CalcIII.aspx
His stuffs are actually very good. Together with Antons I got most of my multi-variables. Check it out. Not for nothing, you can get the used Anton for $4.50 and the other one is free!