Of the relations graphed below, three are functions and one is not.
Which of the relations is NOT a function?
4 graphs. Graph A is a curved line, graph b is horizontal, vertical, and then horizontal, graph C is a line with positive slope, graph D is a parabola.
If it is possible to draw any vertical line (a line of constant x) which crosses the graph of the relation more than once, then the relation is not a function.
