Explanation: For our relation, we have the x-values as inputs and the y-values as outputs. All we need to know is that for a relation to be a function for each input there will be just one and no more than one corresponding output, if so, it is not a function.
Step 1: Let's take a look at our graph to visualise the relation between inputs (x-values) and outputs (y-values)
As we can see above, for x=-4 we have the output 3, for x=6