Posts: 59

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Joined: Jul 2011

Well, it is a bit of historical interest now. But before graphing calculators were widely spread among students it was a very 'popular' exercise in math teaching for 'analyzing a function'. The game was to plot the function by hand. There is a kind of systematic method which was teach intensely to math students. And it is a very concrete and immediate application of the notion of derivative.

Lot of stupid conclusions have been avoided by building a 'table of variations'.

Beside history, it is of interest for functions with discontinuities where graphing algorithms can fail and for getting a firm understanding of a function.

Sometimes it is amazing what you can do with a paper and a pencil, even without an HP calculator....;-)

Posts: 468

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Joined: May 2011

For example the 'variation table' of X^2+3*X+1

In just one glance, you see the essential

On 50G, it's

'X^2+3*X+1' TABVAR