Answer:
It is not an identity
Explanation:
There are 10 common trig identities which I am aware of.
Some are in the image attached
The first image is known as b
Basic Identities
The second are known as Trigonometric / Pythagorean Identities .
The third : Co-function identities
and many more.
I'm only allowed to post five images so that's all I have.