How do you use the vertical line test to determine whether ${(3, - 1), (- 2, 3), (- 1, - 5), (3, 2)}$ ${(3,-1), (-2,3), (-1,-5), (3,2)}$ is a function?

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Answer 1 · 2016-11-06T12:13:58

By definition, in a function, there is only ONE y-value for each x-value.

The vertical line test is used if you have a graph, or if you have plotted the points. A vertical line has the equation $x = n$ $x =n$

If the line intersects the graph more than once, the graph is not a function.

In this case, when $x = 3$ $x=3$ , there are two possible values for y.
$y = - 1$ $y = -1$ OR $y = 2$ $y =2$ (there is a choice of y-values.)

Therefore these points do NOT represent a function.

How do you use the vertical line test to determine whether {(3,−1),(−2,3),(−1,−5),(3,2)}{(3,-1), (-2,3), (-1,-5), (3,2)} is a function?