Answer:
It does not represent a function.
It fails at (3,1), (3,-1), (3,-3.5). The points are variable, the x must stay the same to ensure you tested for VCL.
Explanation:
The vertical line test is the easiest test to see if a line is a function. All you have to do is draw a vertical line across the "function". If AT ANY TIME, the vertical line intersects more than once with the "function", it has failed the vertical line test (VLT) and is not a function.
Please look at the image attached to see how to do the VLT. Please ignore my line drawing and mouse-writing :)