Identifying functions

Which of the following is a function?

• 
• 
• 
• 

What is the definition of function?

• Has inputs and outputs
• Every input has only ONE output
• Inputs have different outputs every time
• x-values and y-values

Which graph is a function?

• Graph 1
• Graph 2
• Graph 3
• Graph 4

Which set of ordered pairs is a function?

• {(9,5), (10,5), (9,-5), (10,-5)}

• {(3,4), (4,-3), (7,4), (3, 8)}

• {(6,-5), (7, -3), (8, -1), (9, 1)}

• {(2, -2), (5, 9), (5, -7), (1, 4)}

Which of these set of coordinates represent a function?

• A
• B
• C
• D