Trigonometry Examples

$\tan (x) = \frac{\sin (x)}{\cos (x)}$

Step 1

Start on the left side.

$\tan (x)$

Step 2

Write $\tan (x)$ in sines and cosines using the quotient identity.

$\frac{\sin (x)}{\cos (x)}$

Step 3

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

$\tan (x) = \frac{\sin (x)}{\cos (x)}$ is an identity