Grapher does this quite well. It comes with Mac OS X and plots various things, 2D and 3D: http://www.google.com/search?q=grapher+mac&hl=en&tbm=isch http://www.g

Grapher does this quite well. It comes with Mac OS X and plots various things, 2D and 3D: http://www.google.com/search?q=grapher+mac&hl=en&tbm=isch http://www.google.com/search?q=grapher+mac&hl=en&tbm... It also formats the equations nicely and lets you copy them as PDF. Makes a decent formula editor for Pages (with simple formulas).