posted by Rick .
Graph one complete cycle of
y + cos x cos pi over6 + sin x sin pi/6 by first rewriting the right side in the form cos(A-B)
You probably meant to write
y = cos x cos pi over6 + sin x sin pi/6 which is
y = cos(x - pi/6)
first sketch very faintly, perhaps as a dotted line, the function y = cosx from 0 to 2pi
then move this graph pi/6 units to the right.