06-10-2010, 12:21 AM
The recent thread about the chalkboard math from the movie "The Day the Earth Stood Still" reminded me of a photo from the current Discover magazine (July/August) advertising a calculus course. I asked my son (recent AP calc student) what was wrong in this picture. Took him about 5 seconds to see the omission. Not that I'm perfect on a chalkboard (or white board) either, but it's a fun past-time to spot these things. Any others out there?
CHUCK