Trigonometry Examples

$\sec^{2} (x) - \tan^{2} (x) = \tan (x) \cot (x)$

Step 1

Start on the left side.

$\sec^{2} (x) - \tan^{2} (x)$

Step 2

Apply pythagorean identity.

$1$

Step 3

Rewrite $1$ as $\tan (x) \cot (x)$ .

$\tan (x) \cot (x)$

Step 4

Because the two sides have been shown to be equivalent, the equation is an identity.

$\sec^{2} (x) - \tan^{2} (x) = \tan (x) \cot (x)$ is an identity