Precalculus Examples

$2 \sec (y) \cos (y) = 2$

Step 1

Start on the left side.

$2 \sec (y) \cos (y)$

Step 2

Apply the reciprocal identity to $\sec (y)$ .

$2 \frac{1}{\cos (y)} \cos (y)$

Step 3

Simplify.

Tap for more steps...

Step 3.1

Combine $2$ and $\frac{1}{\cos (y)}$ .

$\frac{2}{\cos (y)} \cos (y)$

Step 3.2

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

Tap for more steps...

Step 3.2.1

Cancel the common factor.

$\frac{2}{\cos (y)} \cos (y)$

Step 3.2.2

Rewrite the expression.

$2$

Step 4

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

$2 \sec (y) \cos (y) = 2$ is an identity