the "angle 1" means 1 radian, which is about 57.3°, so 1 radian is in quadrant QI,
so cos(q) is positive.
From p to 2p is the region below the x-axis, which includes quadrants QIII and
QIV. Of those two quadrants, the cosine is positive only in QIV.
The angle q in QIV which has 1 radian as its reference angle is found by
subtracting 1 radian from 2p (which is the same as 360°).
Answer: 2p - 1
Edwin
