- Brad Ballinger
- Function Graph
Two ways to represent a function
Left: Cartesian plot.
- Each point on the graph has two coordinates: one for input; the other for output.
- The domain and codomain are assumed to be subsets of , represented as two perpendicular number lines.
- A function passes the vertical line test, which shows that no input has multiple outputs. A function does not have to pass the horizontal line test, though; there may be multiple inputs with the same output.
- Each point represents a single number. Arrows connect input to an output.
- The domain and codomain are assumed to be subsets of , represented as two parallel number lines.
- From any input, there can be at most one output, but (depending on the function) there may be multiple inputs connected to the same output.