Chapter 6.7, Problem 15E

To determine

To find: the value of function by referring to its graph.

Answer to Problem 15E

Undefined

Explanation of Solution

Given information:

  $y=\sec \frac{9\pi }{2}$

The graph of secant is shown below.

Calculation:

The period of the function is $2\pi$ . So, the function will repeat at $2\pi$ intervals. Since $\sec \frac{\pi }{2}$ is equal to $y=\sec \frac{9\pi }{2}$ , where $n$ is the odd integer. The given function can be evaluated as follows:

  $\begin{array}{c}y=\sec \frac{9\pi }{2}\\ =\sec \left(\frac{8\pi +\pi }{2}\right)\\ =\sec \left(\frac{\pi }{2}+4\pi \right)\\ =\sec \frac{\pi }{2}\\ =\text{ undefined}\end{array}$

The value of given function is undefined.