Trigonometry Examples

$\cos^{2} (x) - 1$

Step 1

Rewrite $1$ as $1^{2}$ .

$\cos^{2} (x) - 1^{2}$

Step 2

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = \cos (x)$ and $b = 1$ .

$(\cos (x) + 1) (\cos (x) - 1)$