To determine whether a graph of a relation is also a function, Shayla declares that the y -axis is a vertical line and counts the number of times that the graph intersects the y -axis. If the graph has exactly one y -intercept, Shayla concludes that the graph shows a function. In all other cases, she declares that it is not a function. Is Shayla applying the vertical line test correctly?
Answer
A
Yes, because multiple y -intercepts represent multiple x -values being mapped to y is equal to 0 .
B
Yes, because the y -axis represents all vertical lines of the x -values.
C
No, because the y -axis is a horizontal line.
D
No, because using the y -axis tests only whether x is equal to 0 is mapped to multiple values.