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Comment by dboreham | Hacker News Reader

For the most part "graphing calculator" seems to be a catch all term for "scientific calculator with the features we need" in that little actual graphing is done. But I have seen problems in my son's "Algebra 2" class that require plotting polynomials on the calculator then describing their roots, shape etc. As a way to build intuition about the geometric interpretation of functions, that seems like a reasonable approach although Wolfram alpha would do a decent job too.

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In the UK we have similar questions of plotting and describing geometric functions, however we were simply taught how to plot them by hand, or just directly interrogate the equation to spot where an asymptote might be, roots etc.

IMO this gives a much better inherent understanding of equations, rather than just plugging in some numbers into a calculator and reading what comes out.

Even I have two graphic calculators (HP not TI). I never used them really to draw even a single graph. I mostly use the larger display just to check and copy more easy previous results. On work I prefer these days to use just my HP35S (two lines display / RPN).

And yes, drawing the graph by yourself is for sure the way better way to learn something. But what do we know ...

I wasn't sufficiently clear above: use of graphing software isn't the only way the students are asked to investigate curves: they're taught the methods you're describing too. I presume the idea is to allow a much larger number of curves to be investigated in a given time which sort of makes sense given that the exercise is a form ML training.

Disclaimer: I'm originally from the UK and well versed in "old school" approaches :)

Do you mean the problem gave him a formula and asked him to describe the graph? There's no educational value in using a calculator to generate that graph compared to the graph just being printed alongside the formula. You don't learn by being given the answers before you try to do it yourself. Instead, you need to come up with an answer yourself then check if it's right. The calculator could be useful for checking, but only if the student doesn't use it while they're doing it themselves, otherwise it's no better than copying answers out of the answer book.

The value I can imagine with generating graphs on a calculator would be trying a large number of graphs that are too numerous to print in the text book or to organize in some big table of graphs. That's also the value of a scientific calculator which is faster than looking up trig functions in tables, or a basic calculator that's faster than doing arithmetic by hand.

There's some value in being able to change an equation then immediately see the result in curve shape or position. Basically the same model of curve families, linear transformations, we who are familiar with the subject already have in our brains but not yet present in these students.

> For the most part "graphing calculator" seems to be a catch all term for "scientific calculator with the features we need"

There are a number of scientific calculators that actually do a pretty good job at this, and they’re dirt cheap to boot.

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