Question

Find an angle between -2π and 0 that is coterminal with 5/12π. Express your answer in radians in terms of π.

Answer 1

I'm assuming 5/12pi is (5/12)*pi? Okay, well 5/12pi is greater than 0 but less than pi/2, so it is in the first quadrant. If we're going to move in the opposite direction along the unit circle (through the 4th, 3rd, and 2nd quadrants respectively), we will have to move 2pi - 5pi/12 = 19pi/12 in the negative direction, so... a coterminal angle would be -19pi/12.