Question

Show that sin 8 theta = 8 sin theta × cos theta × cos 2 theta × cos 4 theta​

Answer 1

Answer:

sin 8 theta = sin 2(4theta)

= 2into sin 4 theta . cos 4 theta

2 into 2 sin theta cos 2 theta = cos 4 thta

2 into 2 into 2 sin theta = cos theta cos 2 theta cos 4 theta

8 sin theta cos theta cos 2 theta cos 4 theta