Question

Evaluate cos7pi/6.


-squareroot3/2
-1/2
1/2
squareroot3/2 <<< am i correct

Answer 1

Try again.

Answer 2

\[\LARGE cos\frac{7\pi}{6}=210^○\]
Use the unit circle.
http://i.stack.imgur.com/r8uHr.gif
And remember.
\[\LARGE (x, y)=(cos\theta, sin\theta)\]

Answer 3

You were off by a negative.

Answer 4

@Luigi0210 oh ): thank you!

Answer 5

Anytime.