# Thread: Verifying a trig identity.

1. ## Verifying a trig identity.

cos^2 - sin^2 / cos^2 + sin * cos = 1-tan * 1-cos / cos

You're notation is very confusing, is this the identity?

$\displaystyle \frac{\cos^2x - \sin^2x}{\cos^2x + \sin x \cos x} = \frac{(1-\tan x)( 1-\cos x)}{ \cos x }$

Originally Posted by pickslides
You're notation is very confusing, is this the identity?

$\displaystyle \frac{\cos^2x - \sin^2x}{\cos^2x + \sin x \cos x} = \frac{(1-\tan x)( 1-\cos x)}{ \cos x }$
yea the right side is right but on the left side, 1-tanx is isolated. Don't know if that matters but sorry i don't know how to use better notation