Answer) That graph is not a function
Explanation) The graph that you provided is not a function. It does not pass the vertical line test. The vertical line test is when you draw a vertical line (l) at any point on the graph and it should touch 1 or less parts of the graph. If you put the line at x=1, the vertical line only touches the graph at (1,8.5) but if you put the line at x=5, it touches (5,1) and (5,8.5) so it does not pass the test. You should be able to put the line anywhere and have it touch ONLY 1 point. There cannot be multiple of the same x values.