Trigonometry Examples

$\frac{\sin (x + y) + \sin (x - y)}{\cos (x + y) + \cos (x - y)} = \tan (y)$

Step 1

The provided equation is not an identity.

$\frac{\sin (x + y) + \sin (x - y)}{\cos (x + y) + \cos (x - y)} = \tan (y)$ is not an identity