Chalkboard Math - Printable Version +- HP Forums (https://archived.hpcalc.org/museumforum) +-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html) +--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html) +--- Thread: Chalkboard Math (/thread-168507.html) Chalkboard Math - Chuck - 06-10-2010 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 Re: Chalkboard Math - Bill Zimmerly - 06-10-2010 I believe the middle formula should be Re: Chalkboard Math - Karl Schneider - 06-10-2010 Quote: "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" The derivation looked fine, assuming that the function was f(x) = x2. Was it the missing hash mark from the second "f(x)"? -- KS Edited: 10 June 2010, 1:23 a.m. Re: Chalkboard Math - Vieira, Luiz C. (Brazil) - 06-10-2010 Quote:Was it the missing hash mark from the second "f(x)"?I´d have mentioned the same thing... mostly because the thread refers to an omission. The second line of the derivative evaluation should start with `f'(x)=` instead of `f(x)=` Luiz (Brazil) Edited: 10 June 2010, 7:51 a.m. Re: Chalkboard Math - Walter B - 06-10-2010 FWIW, I concur d:-)