Function or not

• Function
• Not a Function

• Function
• Not a Function

.

• Function
• Not a Function

.

• Function
• Not a Function

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

• Function
• Not a Function

• Function
• Not a Function

used to determine if a relation is a function

• 3d line test
• diagonal line test
• horizontal line test
• vertical line test

Is this set of ordered pairs a function or not a function? 

• Function
• Not a Function