Question

I need an answer to this asap... please ....just number 3

Answer 1

Answer:

hence cos ( 2 A ) = cos 2 A − ( 1 − cos 2 A ) = 2 cos 2 A − 1

Step-by-step explanation:Well we know that for two angles A , B

it holds that cos ( A + B ) = cos A cos B − sin A ⋅ sin B hence for A = B you get cos ( 2 A ) = cos 2 A − sin 2 A But sin 2 A = 1 − cos 2 A

Answer 2

Answer:

is writing an answer

Step-by-step explanation: