I took the Kaplan course and we went over trig functions and unit circle in class. Overall, I was extremely satisfied with Kaplan, however, I feel math is the weakest area of their program. I consistently scored in the 90+ percentile in the quantitative section on all of my practice exams, yet < 50 on actual test day. Luckily I was >90 in every other section and ended up with a 95 composite. I would highly recommend supplementing your kaplan materials with an additional math prep source. Hope this helps... ~Z