I’m not going to try and defend applied math courses taught to engineering students. The quality varies—some are superb, some are pretty meh, some are just bad,

I’m not going to try and defend applied math courses taught to engineering students. The quality varies—some are superb, some are pretty meh, some are just bad, and it can be pretty difficult to tell the difference as a student, especially when a good course assumes you had a good one for a prerequisite when you only had a meh one. I am going to point out that repeatedly asking “why?” will get you into very mathy weeds very quickly, such that “foul” calculus will be the least of your problems. Like here: > As it turns out, most analog filters are relatively distortion-free only in one special case — a perfectly steady sine waveform[.] Ever wonder why? And not just in the sense of showing that’s the right answer, in the sense of setting off without the knowledge of the answer and deriving it. Well, the starting point is that the filter is linear and time-translation-invariant (i.e. doesn’t have a clock built into it); the fact that it is causal is somewhat important but not immediately so. But then things get interesting, and if you’re lucky you’ll get to hear such wonderful phrases as “group characters” and “representation theory”. I don’t blame people who got burned by their math courses, but I do want to emphasize that these kinds of “why?” questions are exactly what math is there for. If the math book in front of you doesn’t look like it works that way, take another one and try again—just don’t expect the specific question you have to be answered immediately. (I’m assuming I don’t have to explain the virtues of repeatedly asking “why?” on a forum called Hacker News.)