Latest Lists

How would you determine from a list of ordered pairs whether it is a function or not?

Example A) { (4,3), (4,2), (4,1), (4,0) } B) { (2,3), (-2,4), (3,9), (-3,9) } C) { (2,8), (3,12), (4,16), (5,20) }

Public Comments

1. Each x-value must have exactly one y-value. For example, (0, 1) and (0, 2) is not a function. (1, 2) and (2, 3) is a function.
2. if x is repeating its not a function, or if its charted and it doesnt make a stright line its not a function
3. By looking at the relationship between the numbers in each pair. It's not a certainty, but it gives an indication of whether a function exists or not.
4. if X=Y ex: Xsquared+5=Y and an easy way to tell if it is NOT a function if X appears twice but with a diffrent Y answers X Y 5 30