Question 4

8 8 8 2 π 3π = 1 − cos 1 − cos 2 (Why?) 8 8 2 π 3π = sin sin 2 8 8 1 π 3π = 1 − cos 1 − cos (Why?) 4 4 4 1 π π = 1 − cos 1 + cos (Why?) 4 4 4 1 π 1 1 1 = 1 − cos 2 = 1− = 4 4 4 2 8 2π 4π