Answer:
Below in bold.
Explanation:
The sine is positive in the first and second quadrants and negative in other 2.
The cosine is positive in the first and 4th quadrants and negative in other 2.
Note that sin(pi/6) = 1/2 and cos(pi/3 = 1/2).
sin(7pi/6) = 1/2
cos(5pi/3) = 1/2
sin(5pi/6) = 1/2