Trigonometry Examples

$\sec (- 90 °)$

Step 1

Find the value using the definition of secant.

$\sec (- 90 °) = \frac{hypotenuse}{adjacent}$

Step 2

Substitute the values into the definition.

$\sec (- 90 °) = \frac{1}{0}$

Step 3

The value of a trigonometric function is undefined when the expression of its value ( $\frac{1}{0}$ ) is an undefined quantity because of division by $0$ .

Undefined