Question

What i did wrong in this?

Answer 1

i) the least positive coterminal angle can be found by subtracting 2pi from your original angle.  We subtract 2pi because 11pi/3 is larger than 2pi.

So: 11pi/3 - 2pi = 11pi/3 - 6pi/3 = 5pi/3 or $\frac{5\pi}{3}$

ii) The reference angle is the smallest angle you can make with the x-axis.  Since 5pi/3 is in Quadrant IV, the reference angle is found by:

2pi - 5pi/3 = 6pi/3 - 5pi/3 = pi/3 or $\frac{\pi}{3}$

iii) 5pi/3 or 300 degrees is found in Quadrant IV.