http://sites.science.oregonstate.edu/portfolioswiki/ 2020-01-26T23:00:29-08:00 http://sites.science.oregonstate.edu/portfolioswiki/ http://sites.science.oregonstate.edu/portfolioswiki/lib/images/favicon.ico text/html 2012-07-08T15:13:21-08:00 http://sites.science.oregonstate.edu/portfolioswiki/whitepapers:differentials:geometry:start?rev=1341785601 Len's dissertation work has uncovered an interesting snippet from a small group: One student labels part of the arc of a circle as $dQ$. The other students initially don't understand the difference between this and $r d\phi$. One of these eventually understands, the other never does.