HOW TO TELL IF AN ARROW DIAGRAM IS A FUNCTION

If each input associates with one output, then it is a function.

Tell whether the relation is a function. Explain.

Problem 1 :

Solution :

The relation is a function.  Because each input value is paired with only one output value.

Problem 2 :

Solution :

The relation is a function.  Because each input value is paired with only one output value.

Problem 3 :

Solution :

The relation is not a function. Because input 5 has associated with more than one output -4 and -3. So, it is not a function.

Problem 4 :

Solution :

The relation is a function. 

Because, there are four input values (-8, -4, 0 and 4). But no values is associated more than one output.

Tell whether the relation is a function. Explain.

Problem 5 :

Solution :

The relation is a function.  Because each input value is paired with only one output value.

Problem 6 :

Solution :

The relation is not a function.  Because 1 is paired with more than one output value (both -1 and 2).