Explanation:
There’s another way to find out if a graph represents a function Instead of doing the horizontal line test or doing the vertical line test, you could find each plot on the graph and see if there’s one or multiple x-axis that has more than one output for a example x=5, y=4 and x=5, y=8 is not a function and a other example is x=15, y=6 and x=15, y=8 is not a function for a other example x=16, y=6 and the x-axis equals nothing else than it’s a function.
To put it in a real life scene it’s like if a guy was dating a girl than he gets with a other girl at the same time , then in mathematical terms that would be not a function and if the guy was not dating anybody else except for one girl, then in mathematical terms it would be a function.
I hope this helped because I probably sent a hour on this answer-_-