No, in order for a set of numbers to be a function, it has to pass the vertical line test. Draw a vertical line to see if it intersects the line more than once. Another way to think about it, is that one singular x value cannot give two different y values. That is impossible.
For example at x = 0, there are two y values that relate to that point. I'm going to estimate the y value for simplicity and the purpose of explanation.
