Comment by arcturus17

> then taking the partial derivative with respect to that variable is equivalent to taking the ordinary derivative of the function

I could not get it for the life of me to actually say this. But it goes on to show, everyone's mileage with the tool varies a lot.

Edit:

I cannot rescue my original prompt, but it was something like:

"Does it make sense to speak of partial derivatives in single-variable calculus?"

I'll grant that it's a more abstract question ("does it make sense") than yours. Or maybe it trips up with the difference between one-dimensional and single-variable. But a half-smart high schooler or college freshman would have understood the question perfectly and made mince meat of it.