Question

how do i know if its an identity or not

Answer 1

D

Answer 2

It is B not D,,

Answer 3

If question is asking about what is the identity here..

Answer 4

\[\large \color{red}{\cos(2x) = \cos^2(x) - \sin^2(x)}\]

Double Angle Identities..

Answer 5

it's D

Answer 6

its just asking which of the follwing are identities can be more than one!!

Answer 7

Yes sorry..

D is also right..

Answer 8

thanks again

Answer 9

\[\tan(x - \pi) \implies \tan(-(\pi - x)) \implies -\tan(\pi - x) \implies -(-\tan(x)) \implies \color{blue}{\tan(x)}\]

\[\cos(x + y) + \cos(x - y) = 2\cos(x)\cos(y)\]