Precalculus Examples

$\tan (θ) \cot (θ) = 1$

Step 1

Start on the left side.

$\tan (θ) \cot (θ)$

Step 2

Convert to sines and cosines.

Tap for more steps...

Step 2.1

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

$\frac{\sin (θ)}{\cos (θ)} \cot (θ)$

Step 2.2

Write $\cot (θ)$ in sines and cosines using the quotient identity.

$\frac{\sin (θ)}{\cos (θ)} \cdot \frac{\cos (θ)}{\sin (θ)}$

Step 3

Simplify.

Tap for more steps...

Step 3.1

Cancel the common factor of $\sin (θ)$ .

Tap for more steps...

Step 3.1.1

Cancel the common factor.

$\frac{\sin (θ)}{\cos (θ)} \cdot \frac{\cos (θ)}{\sin (θ)}$

Step 3.1.2

Rewrite the expression.

$\frac{1}{\cos (θ)} \cos (θ)$

Step 3.2

Cancel the common factor of $\cos (θ)$ .

Tap for more steps...

Step 3.2.1

Cancel the common factor.

$\frac{1}{\cos (θ)} \cos (θ)$

Step 3.2.2

Rewrite the expression.

$1$

Step 4

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

$\tan (θ) \cot (θ) = 1$ is an identity