Solving Really Hard Trig Equations (with factoring!)

If you're lucky, maybe your teacher won't even make you do these, especially if you're not in honors. But for most kids, this will be the worst factoring problems you'll ever see. Stuff like sin²x-2sin+1=0, cos²x+2cosx-3=0, and 3tan²x-4tanx-5=0. (Notice I didn't say worst trig equations, because I'll reserve that honor for equations with a number in front of the x!)