How do you know if a graph is a function?
Understand the Problem
The question is asking us to identify the criteria that determine whether a graph represents a function. It is necessary to consider characteristics of functions, particularly the vertical line test, which states that if any vertical line intersects the graph more than once, then the graph does not represent a function.
Answer
Use the vertical line test: a graph is a function if every vertical line intersects it at most once.
A graph is a function if every vertical line intersects the graph at most once.
Answer for screen readers
A graph is a function if every vertical line intersects the graph at most once.
More Information
Vertical Line Test: This is a standard method of determining if a graph is a function. If any vertical line crosses the graph more than once, then it is not a function.
Tips
A common mistake is confusing the vertical line test with the horizontal line test, which is used to determine if a function is one-to-one.
Sources
- Testing if a relationship is a function - khanacademy.org
