There used to be an entry here that the trigonometric functions for angles => 90° had not been dealt with. I am putting this reminder here. That surely comes before trig identitites. RoseParks
I removed it because the unit circle section takes care of all angles. The section and graphic could use refinement, but that's what the wikipedia is for :).----
I see box for a graphic of a unit circle, but no graphic? Anyone else see it?? RoseParks