Question

which of the following are identities? (Answers listed below)

Answer 1

Looks like a quiz question.

Answer 2

There are two, so you need to choose all that apply.
"which of the following \(are \) identities"

If you are stuck, put some arbitrary values for x and y and see which ones do \( not \) work, and eliminate them.
The best approach is to study the double angle formulae, and check the identities.

Answer 3

I know that A. is an answer, and I think that B and D are NOT answers but i don't know about C

Answer 4

nevermid i got it, thanks :)

Answer 5

Look up the standard curve of tan(x), and you will see readily!

Answer 6

Perfect!