Functions: the chart with number values, the dot graph, and the middle graph on the right
Not functions: the top graph on the left with the vertical line, the graph with the circle, and the bottom right graph
Any graph that doesn’t pass the vertical line test is not a function. You can do this by starting at the top of the graph and drawing a line straight down through what you are testing. If you pass through the line or circle more than once it is not a function.
If you look at the number values if the x value repeats more than once it is not a function.