EDGE Math 8

Vertical Line Test

Example 6

Graph the following equation:

y = \frac{6}{x}

Then use the vertical line test on each graph to identify if its equation defines y as a function of x.

Solution

Construct a table of ordered pairs for the equation $y = \frac{6}{x} .$ Substitute –2, –1, 1, and 2 for x and solve for the corresponding values of y.

Value of x	Value of $y = \frac{6}{x}$	Ordered Pair $(x, y)$
−2	$y = - 3$	$(- 2, - 3)$
−1	$y = - 6$	$(- 1, - 6)$
1	$y = 6$	$(1, 6)$
2	$y = 3$	$(2, 3)$

Using the vertical line test, you can see that the graph of $y = \frac{6}{x}$ is that of a function.