Trigonometry Examples

$\cos^{2} (45) - \sin^{2} (45)$

Step 1

Apply the cosine double-angle identity.

$\cos (2 \cdot 45)$

Step 2

Multiply $2$ by $45$ .

$\cos (90)$

Step 3

The exact value of $\cos (90)$ is $0$ .

$0$