To analyze the function \( f(x) = \sec(x) \), let's go through each statement provided:
-
\( (0, 1) \) is a point on the graph:
We can evaluate \( f(0) \): \[ f(0) = \sec(0) = \frac{1}{\cos(0)} = \frac{1}{1} = 1. \] So, the point \( (0, 1) \) is indeed on the graph. (True) -
\( f(x) \) is defined for all \( x \):
The secant function is defined as \( \sec(x) = \frac{1}{\cos(x)} \). The function is undefined wherever \( \cos(x) = 0 \), which occurs at odd multiples of \( \frac{\pi}{2} \). Therefore, it is not defined for all \( x \). (False) -
There is a vertical asymptote at \( x = \frac{\pi}{2} \):
Since \( \cos\left(\frac{\pi}{2}\right) = 0 \), \( \sec\left(\frac{\pi}{2}\right) \) is undefined, and there is indeed a vertical asymptote at this point. (True) -
\( f(x) \) is undefined when \( \sin x = 0 \):
The secant function is related to cosine, not sine. The function is actually undefined when \( \cos x = 0 \), which is not necessarily when \( \sin x = 0 \). The values of \( x \) for which \( \sin x = 0 \) are \( n\pi \) (where \( n \) is an integer), and those points do not include vertical asymptotes (the function is defined there). (False) -
All x-values are included in the domain:
As discussed, since the secant function is undefined at odd multiples of \( \frac{\pi}{2} \), not all x-values are included in the domain. (False)
In summary, the true statements regarding the graph of \( f(x) = \sec(x) \) are:
- \( (0, 1) \) is a point on the graph.
- There is a vertical asymptote at \( x = \frac{\pi}{2} \).