Graph the relation {(5, 0), (0, 5), (5, 1), (1, 5)}. Is it a function? Why or why not?

No, it does not pass the horizontal-line test.

Yes, it passes the vertical-line test.

No, it does not pass the vertical-line test.

Yes, it passes the horizontal-line test.

1 answer

To determine if the given relation \({(5, 0), (0, 5), (5, 1), (1, 5)}\) is a function, we need to apply the definition of a function: each input (or x-value) must correspond to exactly one output (or y-value).

Let's evaluate the x-values in the relation:

  • The point \((5, 0)\) has an x-value of 5.
  • The point \((0, 5)\) has an x-value of 0.
  • The point \((5, 1)\) also has an x-value of 5.
  • The point \((1, 5)\) has an x-value of 1.

Here, we see that the x-value of 5 corresponds to two different y-values: 0 and 1. Because of this, the input 5 does not have a unique output.

Therefore, the relation does not satisfy the criteria of a function.

Conclusion:

No, it does not pass the vertical-line test.

In a graphical sense, if we were to plot these points, drawing a vertical line at \(x = 5\) would intersect the graph at two points, which confirms that it is not a function.