He may actually not know. People who teach maths are often not terribly good at it. Why don’t you post the equation and the thing he turned it into? One of us will probably be able to see what is going on.
In all fairness, at university, being lectured by people whose job was maths research and who were truly world class at it, I remember similar happenings. Although they have subtler ways of telling you to shut up. Figuring out what’s going on between the steps of a proof is half the fun and it tends to make your head explode with joy when you finally get it.
I just gave a couple of terms of first year maths lectures, stuff that I thought I knew well, and the effort of going through and actually understanding everything I was talking about turned what was supposed to be two hours a week into two days a week, so I can quite see why busy people don’t bother. And in the process I found a couple of mistakes in the course notes (that of course get passed down from year to year, not rewritten from scratch with every new lecturer).
He may actually not know. People who teach maths are often not terribly good at it. Why don’t you post the equation and the thing he turned it into? One of us will probably be able to see what is going on.
In all fairness, at university, being lectured by people whose job was maths research and who were truly world class at it, I remember similar happenings. Although they have subtler ways of telling you to shut up. Figuring out what’s going on between the steps of a proof is half the fun and it tends to make your head explode with joy when you finally get it.
I just gave a couple of terms of first year maths lectures, stuff that I thought I knew well, and the effort of going through and actually understanding everything I was talking about turned what was supposed to be two hours a week into two days a week, so I can quite see why busy people don’t bother. And in the process I found a couple of mistakes in the course notes (that of course get passed down from year to year, not rewritten from scratch with every new lecturer).