Trigonometry Examples

$\sec (- \frac{2 π}{3})$

Step 1

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

$\sec (\frac{4 π}{3})$

Step 2

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 third quadrant.

$- \sec (\frac{π}{3})$

Step 3

The exact value of $\sec (\frac{π}{3})$ is $2$ .

$- 1 \cdot 2$

Step 4

Multiply $- 1$ by $2$ .

$- 2$