Precalculus Examples

$\sec (120)$

Step 1

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because secant is negative in the second quadrant.

$- \sec (60)$

Step 2

The exact value of $\sec (60)$ is $2$ .

$- 1 \cdot 2$

Step 3

Multiply $- 1$ by $2$ .

$- 2$