Learn about the vertical line test for functions.

A function only has one y-value for each x-value, so graphically a vertical line placed anywhere on the graph of the function should intersect the function in at most one place.

Learn about the vertical line test for functions.

A function only has one y-value for each x-value, so graphically a vertical line placed anywhere on the graph of the function should intersect the function in at most one place.