Question

Find one positive and one negative angle coterminal with an angle of 9pi/6

Answer 1

21pi/6 and -3pi/6.

Explanation:

We add or subtract 2pi from the angle:

9pi/6 + 2 pi

= 9pi/6 + 12pi/6

= 21pi/6 is the positive angle

9pi/6 - 2pi

= 9pi/6 - 12pi/6

= -3pi/6.