Answer: yes
Step-by-step explanation: I think that the least confusing way to do this problem is to first write down the ordered pairs that are represented by this mapping diagram.
So we have {(6, -1), (-1, 2), (4, 3), (0, 3)}.
In order for this relation to be a function, the x-coordinate can only
appear once unless we have the same ordered pair more than once.
Since each x-coordinate does appear once, it must be a function.
Students often make the mistake of saying this relation is not a function
because we have the same y-coordinate in two different ordered pairs, 3.
In other words, looking at the mapping diagram students will say that this relation is not a function because we have two x's paired with the same y.
Remember however that the definition of a function doesn't
say that each x must be paired with a different y.
It says that each x must be paired with exactly one y.
So in summary, a function can have the same y-coordinate in
two different points, just not the same x-coordinate.
The exception to this would be if the same ordered pair
is listed more than once in which it would be a function.
