Definition talk:Cosine/Definition from Circle

I'm interested in knowing what the motivation for defining the trigonometric functions separately for each quadrant is --Ybab321 (talk) 16:08, 30 July 2013 (UTC)


 * How else do you do it? --prime mover (talk) 18:50, 30 July 2013 (UTC)


 * Well the same thing is written for each quadrant. Why not speak for the circle as a whole? --Ybab321 (talk) 17:54, 31 July 2013 (UTC)


 * Got to be explicit, otherwise it's not clear. --prime mover (talk) 18:26, 31 July 2013 (UTC)