Question

Which of the following statements explains why the set of ordered pairs does NOT define a function?

{(3,6), (4,8), (5,10), (3,1), (6,12), (7, 10)}

A
Some ordered pairs use x and y values of different signs.

B
Some ordered pairs use the same number for both the x and y values.

C
Some ordered pairs use the same x value with different y-values.

D
Some ordered pairs use the same y value with different x values.

Answer 1

Answer: C) Some ordered pairs use the same x value with different y values.

With any function, any input x must lead to exactly one y output.

The input x = 3 leads to y = 6 and y = 1 for the first and fourth points shown. So this is the reason why we do not have a function.

Graphing (3,6) and (3,1) shows that a single vertical line passes through them both. This means the relation fails the vertical line test.