A company called Desmos (that I know nothing about), has launched a free online graphing calculator. What’s beautiful about this one, aside from its ease of use and powerful graphing abilities, is that it uses HTML 5. I know nothing about HTML 5, other than it makes things work on iPads.
This is a screenshot from my iPad.
Their calculator is at www.abettercalculator.com . Try it out. Play around with it.
Making sliders for students to play with is simple. Just type in “a=1″ and a slider appears. Now write a function that has “a” in it, and your slider just works.
Here’s one I made with four sliders for a trig function.
It doesn’t work on my iPhone (yet?), but the iPad looks great. Manipulating the sliders on the iPad takes a little getting used to, but after that, they work beautifully.
This one is well worth the price.