Well.... I just finished Algebra II, but I hated Unit Circle..... bleh
(x,y)
(cos[theta], sin[theta])
(4,-8)
So for cos to be POSITIVE, it can only be in either Quadrant I, or Quadrant IV
Quad I = (+,+)
Quad IV = (+,-) (Our cord has a negative sin, so that is it)
So it has to be in Quad IV, that is some information.
That narrows it down to either A or B.
If you have a calculator, you can put in:
cos(-2) or cos(-2/sq rt 5) i believe.... or its either the inverse, can’t entirely remember.
Im sorry I couldn’t help you more.
