Skip to main content
3 events
when toggle format what by license comment
Dec 24, 2011 at 21:09 comment added Will Sawin If this argument worked, it would work equally well if you weren't moving on a level curve, but were instead following some other path.
Aug 23, 2011 at 22:02 comment added Sridhar Ramesh The problem here is the unfortunate notation for partial derivatives: the top $\partial U$ represents $dU=U_x dx+U_y dy$ with $dy$ set to zero, while the bottom $\partial U$ represents $dU$ with $dx$ set to zero; the $\partial$ represents a different differential operator in the two cases, even though it is written with the same symbol. This is somewhat orthogonal, though, to the issue of whether it is appropriate to view all these ratio-looking things as ratios; the problem isn't in treating ratio-type things as ratios, but in not notationally distinguishing different operators.
Aug 23, 2011 at 15:06 history answered Steven Landsburg CC BY-SA 3.0