Heptadecagon

Each semester, I tell the students to ask questions if they have them. The more they question me, the more I understand if they comprehend the material or not. I've even gone so far as to say to a class, "If you don't understand a concept, but you're not sure what question to ask, still contact me. I can probably help." Of course I can help: I'M THE PERSON WHO WRITES THE EXAMS FOR THE COURSE. I'm also really qualified to be teaching the class, and that's not being a braggart, it's stating a fact. Finally, the other night, I received this email: "I am having a hard time understanding F=P/R and P=HR x SV x R. I understand how you get to that equation, but what I don't understand is how those all regulate blood pressure. I'm not really sure how to ask a question." Aha! So they do listen to me at times! Well, to be quite honest, talking about blood flow (F), blood pressure (P or more accurately ΔP), and resistance (R) is a dif...