Question

Which of the following relations is a function?

A{(3,-1), (2, 3), (3, 4), (1,7)}

B{(1, 2), (2, 3), (3, 4), (4, 5)}.

C{(3, 0), (4, -3), (6, 7), (4,4)}

D{(1, 2), (1, 3), (2, 8), (3, 9)}​

Answer 1

B.

Explanation:

Well a relation is a set of points and a function is a relation where every x value corresponds to only 1 y value.

So lets see which x values in these relations have only 1 y value.

A. Well a isn’t a function because the number 3 which is a x value had two y values which are -1 and 4.

B. This relation is a function because there are no similar x values.

C. This is not a function because the x value 4 has two y values which are 4 and -3.

D. This is not a function because the number 1 has 2 and 3 as y values.

Answer 2

B

Explanation:

A is not a function because the same x value is repeated twice with different y values. The same goes for C and D so the answer is C.