John’s comment got me thinking — wouldn’t it be great if Illustrator allowed you to type in algebra to generate perfectly formed paths? Is there another vector editor that can do it?
And then I remembered OS X’s great Grapher app, which can be found in your Utilities folder. Grapher can save EPS and PDF files, which can be opened in Illustrator for cleanup and use.
I think I’m going to use this technique a fair bit, for tricky shapes that would be best built with algebra. Being able to adjust the algebra and see live results really helps fine tune things. And, Grapher can save documents and formulas for later use.