Question

I need help...Which table represents a function?

A 2-column table with 4 rows. The first column is labeled x with entries negative 3, 0, negative 2, 8. The second column is labeled y with entries negative 1, 0, negative 1, 1.

A 2-column table with 4 rows. The first column is labeled x with entries negative 5, 0, negative 5, 6. The second column is labeled y with entries negative 5, 0, 5, negative 6.

A 2-column table with 4 rows. The first column is labeled x with entries negative 4, negative 2, negative 2, 0. The second column is labeled y with entries 8, 2, 4, 2.

A 2-column table with 4 rows. The first column is labeled x with entries negative 4, 3, 1, negative 4. The second column is labeled y with entries 2, 5, 3, 0.

Answer 1

Answer: Choice A

Step-by-step explanation:

A function has each x value map to exactly one y value. Choice A demonstrates this, which is why it's a function. Note how none of the x values are repeated in this table.

Choices B, C and D have repeated x values, which in turn means that we have an x input lead to multiple y outputs. For instance, choice B says that the input x = -5 has the two outputs y = -5 and y = 5; this is sufficient to show that table B is not a function. Choices C and D are a similar story.