MathTV is a real problem solver for many. It is also found on YouTube, and is free. Here is some background.
posted by Brian B. on Mar 21, 2009 - 8 comments

Norman Wildberger's New Trigonometry Dr Norman Wildberger has rewritten the arcane rules of trigonometry and eliminated sines, cosines and tangents from the trigonometric toolkit. The First chapter of his new book, Divine Proportions, is online (.pdf).
posted by Kwantsar on Sep 25, 2005 - 21 comments

64=65? there must be some kind of trick to this, right?
posted by pyramid termite on Aug 18, 2004 - 30 comments