a. Express sin x 3 cos x in the form R sin (x ), with R > 0 and 0 < <

a. Express sin x − √3 cos x in the form R sin (x − α), with R > 0 and 0 < α < 90°.

b. b Hence sketch the graph of y = sin x − √3 cos x, for −360° < x < 360°, giving the coordinates of all points of intersection with the axes.