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put this solution on YOUR website!First consider what it means to be a function. If
f is a function, then, if you take one value for x, you will find one and only one value for y. To put this in a different way, if you can find an x value that produces more then one y value, then the relation is not a function.
Next, consider this problem. Look at all of the x values, they are 0, 1, 2, 3 and 4. In each case, the x value produces one and only one y value, so the relation must be a function.
To make the point clear, let's pretend we add (0,2) to the relation. This means, the x value 0 can produce two y values, 1 and 2. Under this condition, the relation is not a function.
Since the problem tells you all of the possible x, y combinations, the relation must be a function.