Vertical Line Test

A method used to determine if a graph represents a function. If a vertical line intersects the graph at more than one point, it is not a function.

A graph is a function if every input (x-value) has exactly one output (y-value).

The graph of y = x^2 is a function because each x-value has one corresponding y-value.

The graph of a circle, such as x^2 + y^2 = r^2, is not a function because a vertical line can intersect it at two points.

If any vertical line drawn on the graph intersects it at more than one point, then the graph is not a function.

The set of all possible input values (x-values) for the function.

The set of all possible output values (y-values) for the function.

No, a function cannot have multiple outputs for a single input; this would violate the definition of a function.

A function that graphs to a straight line, represented by the equation y = mx + b.

A function that does not graph to a straight line, such as quadratic functions, exponential functions, etc.