In September last year, I shared to you about the Peanut Software Package, a mathematics software collection by Philip Exeter University. One of the software in the collection is Winplot, a powerful graphing software capable of drawing and animating curves and surfaces. If you want to learn about Winplot, I discovered a collection of flash video tutorials here.
The tutorials includes basic graphing, finding critical points of graphs of functions, inequalities, piecewaise functions, plotting trigonometric functions, polynomial regressions and integration.
Winplot is free and available on Windows operating systems. It has also a 3D graphing capability as shown above.