D Danny New member Dec 13, 2009 #2 Simple. All you do is draw a vertical line through any point on the graph. If the line only passes through one point, the graph is a function. If the line passes through two or more points on the graph, it is not a function.
Simple. All you do is draw a vertical line through any point on the graph. If the line only passes through one point, the graph is a function. If the line passes through two or more points on the graph, it is not a function.