Question

Which of the following mapping diagrams does not represent a function?

Answer 1

C does not represent a function. It is not a function because the value x = 7 maps to more than one y value 

Remember that for a function, for every x value there is only one value for y.

Answer 2

Answer: Option C

Step-by-step explanation:

In a function, each element of the domain has only one adjusted element in the range (but one element in the range can have more than one element adjusted in the domain.)

We can see that the only diagram that has this problem is the diagram C (the 7 in the domain is associated to the 8 and the 12 in the range), while the other two diagrams can represent functions.