Question

Cos4a=1-8sin^2a+8sin^4a

Answer 1

I hope you will be satisfied by my solution

Answer 2

Answer:

cos 4A

= cos (2 ∙ 2A)

= cos\(^{2}\) (2A) - sin\(^{2}\) (2A)

2. Express cos 4β in terms of sin 2β

Solution:

cos 4β

= cos (2 ∙ 2β)

= 1 - 2 sin\(^{2}\) (2β)