In Example 8, in the second line, change “to the right 3 units and down 2 units” to “to the left 2 units and down 3 units.”

Data from Example 8

Use the vertical line test to determine whether the relation y² = x represents a function. By letting x = 0, 1, and 4, we get the table and graph shown in Fig. 3.22.

Note that any positive value of x has two corresponding values of y. Since a vertical line crosses this graph twice, this relation is not a function.

Fig. 3.22.

-1 2 1 0 -1 -2 C 1 2 3 |x=y2 5 X