Precalculus Examples

$\sec (\frac{- 7 π}{2})$

Step 1

Rewrite $\sec (\frac{- 7 π}{2})$ in terms of sines and cosines.

$\frac{1}{\cos (\frac{- 7 π}{2})}$

Step 2

Move the negative in front of the fraction.

$\frac{1}{\cos (- \frac{7 π}{2})}$

Step 3

Add full rotations of $2 π$ until the angle is greater than or equal to $0$ and less than $2 π$ .

$\frac{1}{\cos (\frac{π}{2})}$

Step 4

The exact value of $\cos (\frac{π}{2})$ is $0$ .

$\frac{1}{0}$

Step 5

The expression contains a division by $0$ . The expression is undefined.

Undefined