The Museum of HP Calculators

HP Forum Archive 19

 Chalkboard MathMessage #1 Posted by Chuck on 10 June 2010, 12:21 a.m. 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 MathMessage #2 Posted by Bill Zimmerly on 10 June 2010, 1:15 a.m.,in response to message #1 by Chuck I believe the middle formula should be

 Re: Chalkboard MathMessage #3 Posted by Karl Schneider on 10 June 2010, 1:22 a.m.,in response to message #1 by Chuck 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 MathMessage #4 Posted by Vieira, Luiz C. (Brazil) on 10 June 2010, 7:48 a.m.,in response to message #3 by Karl Schneider Quote:Was it the missing hash mark from the second "f(x)"?IŽd 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 MathMessage #5 Posted by Walter B on 10 June 2010, 5:25 p.m.,in response to message #4 by Vieira, Luiz C. (Brazil) FWIW, I concur d:-)

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