Function or not review for makeup

Is this mapping a function or not a function? 

• Function
• Not a Function

Is this graph a function or not a function? 

• Function 
• Not a Function

Is this mapping a function or not a function? 

• Function
• Not a Function 

Is the graph pictured a function?

• Yes
• No

.

• Function
• Not a Function

• Function
• Not a Function