Use a graphing calculator to make a conjecture as to whether each equation is an identity.
-$$\cos 2 x = 2 \cos ^ { 2 } x - 1$$
A) Identity
B) Not an Identity

Question

Quizplus · Accepted Answer

The equation $\cos 2x = 2\cos^2x - 1$ is a well-known trigonometric identity, which can be verified using trigonometric identities or by graphing both sides of the equation and observing that they produce the same graph for all values of $x$.

Use a Graphing Calculator to Make a Conjecture as to Whether