Question

3. Which relation is a function?

A. {(-3, 4), (-3, 8), (6, 8)}
B. {(3, 4), (-3, 8), (6, 8)}
C. {(-3, 4), (3,-8), (3, 8)}
D. {(-3, 4), (3,5), (-3, 8))​

Answer 1

B

Explanation:

Recall that functions are defined only if for each value in the domain produces one and only one value in the range.

If we view the relations in the questions as x-y coordinates, this means that for every x-value, you can only have one y-value

Lets evaluate the options:

A) we can see that for x = -3, this gives 2 possible values for y i.e (-3,4) and (-3,8) (hence this is not a function)

C) we can see that for x = 3, this gives 2 possible values for y i.e (3,-8) and (3,8) (hence this is not a function)

D) we can see that for x = -3, this gives 2 possible values for y i.e (-3,4) and (-3,8) (hence this is not a function)

the only choice where this doesn't occur is choice B