The trick to picking out functions is to pay attention to the x- coordinates.
Why is it important to pay attention to the x - coordinates in a function?
Functions are relationships between variables, where each input (x-coordinate) corresponds to a unique output (y-coordinate). This means that the x-values should not repeat, ensuring that each input corresponds to a distinct output.
When examining a graph or data set, look for patterns in the x-coordinates. If there are no repeating x-values, it suggests that the relationship is functional. On the other hand, if the same x-value appears multiple times with different y-values, it indicates that the relationship is not functional.