Question

Help ?!?!?!?!

Answer 1

cos 2 θ =2 cos^2 θ−1

Answer 2

Is this a proof?

Answer 3

idk Use an angle sum identity to verify the identity
cos 2 theta = 2 cos^2 theta - 1 is all they ask

Answer 4

It's not an identity. I think that's the answer they are looking for.

Answer 5

o ok so just say no idenity as my answer

Answer 6

Yeah.

Answer 7

ok thanks

Answer 8

you have to verify ...

Answer 9

ok so how do i do that

Answer 10

\[\cos^2(\theta) + 1 = 2 \cos^2(\theta) \]
\[1 = \cos^2(\theta)\]
NOT An ItNDITY

Answer 11

cos 2 theta = cos^2 theta - sin^2 theta
is the formula

Answer 12

@abb0t so should I write that as my answer

Answer 13

yeah.