Answer:
Part A - Represents a function
Part B - Doesn't represent a function.
Explanation:
A set is just a list of numbers to check. The question is asking you based on the set...
(-5, 8)
(-6, 2)
(-2, -6)
(-1, 8)
(4,6)
if it is a valid function.
At NO point should a function have multiple x values. This fails the Vertical Line Test if visualized on a graph.
For Part A, there are no duplicate x values, meaning this function is valid.
For Part B, there is a duplicate x value - (2,9) & (2,4). Because of this, immediately the function is invalid. There can not be any duplicate x values in a valid function, PERIOD. If graphed, it fails the vertical line test.