Precalculus Examples

$\cos (- θ) - \cos (θ)$

Step 1

Since $\cos (- θ)$ is an even function, rewrite $\cos (- θ)$ as $\cos (θ)$ .

$\cos (θ) - \cos (θ)$

Step 2

Subtract $\cos (θ)$ from $\cos (θ)$ .

$0$