Question

if the coterminal angle of cos 420 equals 60 degrees, then what is cos 420?

Answer 1

1/2. It's the same as if it was 60.

Answer 2

can you explain why?

Answer 3

If you traced around the circle 420 degrees it gets you to the same point as if it just equaled 60. Therefore whenever you have a degree measurement like that that you need to find the sin or cos for you can subtract 360 from it as many times as you need until you get to the value between 0 and 360.

Answer 4

ok. that makes more sense. thanks!