Final answer:
To decide if a relation is a function, graph the relation and check if any vertical lines intersect the graph in more than one point.
Step-by-step explanation:
Question:
For each relation, decide whether or not it is a function.
Answer:
A function is a relation where each input has only one output. To determine if a relation is a function, you can use the vertical line test. If any vertical line intersects the graph of the relation in more than one point, then it is not a function. However, if every vertical line intersects the graph in at most one point, then it is a function.
So, to decide whether a relation is a function or not, graph the relation and check if there are any vertical lines that intersect the graph in more than one point.