Question

Which ones is a function? thank you!

Answer 1

B (first row)

Explanation:

(A) is not a function because it fails the vertical line test (the line will intersect the graph in more than one place).

(B) is a function because it passes the vertical line test; the vertical line intersects the graph at only one place.

Answer 2

1. B

2. A

3. B

Explanation:

1. Can be checked using the vertical line test. By placing a vertical line at any x value, there can only be one point at which the line meets a part of the graph.

2. An x value can only correspond to one y value. B is incorrect since the x value of 5 is both -4 and 1 for the y values.

3. Same as above but with x and y charts. A x value can only correspond to one y value. A is incorrect as two of the same x values (2) appears and corresponds to two different y values (5 and 6).