Given:
A set of ordered pairs.
Required: Check whether each is a function.
Explanation:
A function is a relation from a set of inputs to a set of possible outputs where each input is related to exactly one output.
3. The input -13 has 2 output values 4 and 9. Hence it is not a function.
4. Each input has exactly one output. There fore, it is a function.
Final Answer:
3. Not a function