1 Each of the graphs below is also represented by a table. Use the vertical line test to determine whether or not each graph represents a function.
Function or Not a Function? 
Function or Not a Function? 
Function or Not a Function? 




2 For each graph that failed the vertical line test, label the offending points with their coordinates.
3 Find the same coordinates in the table below the graph and circle or highlight them.
4 What do the tables of the nonfunctions have in common? What could you look for in other tables to identify whether or not they could represent a function?
5 Use the process you just described to determine whether each table below could represent a function. Circle or highlight the points that would end up on the same vertical line.





Function or Not? 
Function or Not? 
Function or Not? 
Function or Not? 
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