Question

8sinϴ x cosϴ x cos2ϴxcos4ϴ​

Answer 1

Answer:

we known: sin 2@=2 sin@ cos@

8 sin@ cos@ cos2@ cos4@=sin x

2 2 (2 sin@ cos@) cos2@ cos4@=sin x

2 (2 (sin2@) cos2@) cos4@=sin x

2 sin4@ cos4@=sin x

sin 8@=sin x

(@=theta)

∴ x = 8 theta