f we start at the point (1,0) and travel once around the unit circle, we travel a distance of 2pi units and arrive back where we started at the point (1,0).

f we start at the point (1,0) and travel once around the unit circle, we travel a distance of 2pi units and arrive back where we started at the point (1,0). If we continue around the unit circle a second time, we will repeat all the values of x and y that occurred during our first trip around. Use this discussion to evaluate the expression sin(2pi - pi/2)