Question

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?
No, because the y-axis is a horizontal line.
No, because using the y-axis tests only whether x = 0 is mapped to multiple values.
Yes, because multiple y-intercepts represent multiple x-values being mapped to y = 0.
Yes, because the y-axis represents all vertical lines of the x-values.

Answer 1

Answer: Choice B

No, because using the y-axis tests only whether x = 0 is mapped to multiple values.

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Further Explanation:

Shayla stating that the y axis being used to conduct a vertical line test is part of the process. But she needs to move the vertical line around and not have it fixed in place.

If it is possible to have a vertical line (on the y axis or not) pass through more than one point on the curve, then we don't have a function. It is said the curve fails the vertical line test.

Otherwise, the graph passes the vertical line test and we have a function.