Unit Circle Problems?

Question

Find the exact value of the trigonometric function at the given real number

11. a) cos 7pi/3

How would you do this since there is no 7pi/3 on a unit circle?

http://www.embeddedmath.com/downloads/files/unitcircle-letter.pdf

is the unit circle i have

oh and i didnt know how to make the pi sign on the computer sorry

Answer 1

7pi /3 = 2 1/3 pi same as pi/3 (going around the circle once)

cos pi/3 =1/2

Answer 2

For most trigonometric function,

you can add or subtract 2 Pi anytime.

Do it like pi/3

I believe you can work it out from here.