What is an example of a graph that fails the vertical line test?

Related questions

• What is Vertical Line Test?
• How do you use the vertical line test?
• When is a relation a function?
• How do you determine if the following sets of points is a function: #{(2,3), (-1, 3), (4, 7), (-1, 5)}#?
• Why does the vertical line test work?
• Does a linear graph pass the vertical line test?
• Does a vertical line pass the vertical line test?
• What is the vertical and horizontal line tests for 1-1 function?
• Is {(–2, 4), (5, 8), (3, 6), (5, 9)} a function?
• Is {(8, –1), (–8, 1), (6, –1), (8, 6)} a function?