Comment on The pi is a lie… Happy Half Tau Day!parentComments−_cbsz15yFor the sake of completeness, cos is the x value, because of the identity sin(x)^2 + cos(x)^2 = 1. You should find a good unit circle trigonometry picture if your class isn't giving it to you.Wikipedia's picture is frightening (http://en.wikipedia.org/wiki/Unit_circle), but perhaps http://www.themathpage.com/atrig/unit-circle.htm or http://www.snow.edu/jonathanb/Courses/Math1060/unit_circ_tri... will help.
Comments
For the sake of completeness, cos is the x value, because of the identity sin(x)^2 + cos(x)^2 = 1. You should find a good unit circle trigonometry picture if your class isn't giving it to you.
Wikipedia's picture is frightening (http://en.wikipedia.org/wiki/Unit_circle), but perhaps http://www.themathpage.com/atrig/unit-circle.htm or http://www.snow.edu/jonathanb/Courses/Math1060/unit_circ_tri... will help.