Yes, the vertical line test can be used to determine whether a relation is a function. The test states that if a vertical line intersects the graph of a relation in more than one point, then the relation is not a function. If a vertical line intersects the graph of a relation in only one point or does not intersect the graph at all, then the relation is a function. Without the graph being provided, it is not possible to determine whether the relation is a function using the vertical line test. Therefore, the answer is "cannot be determined".
