From: Fleck Jean-Julien Date: 2009-12-23T16:51:08+09:00 Subject: Re: Trig value errors > Again, one really simple fix to eliminate these ERRORS Well, what you are looking for is Maple, Mathematica or Octave, some kind of symbolic mathematics software. They all have worked very hard to make all those kind of things consistent in a mathematical point of view. But even there you can still quite easily find "mathematical bugs" that is results that are not in the simplest form expected even by my least gifted students. Cheers, -- JJ Fleck PCSI1 Lycée Kléber