Is the relation a function? y = x2 + 12x + 31

Yes , is a function.

Step-by-step explanation:

The given relation :

where , and it a polynomial function .

Also, when we draw the graph of the given function  [see the attachment ], we can see that each value of x corresponds to exactly one unique y-value.

It means it follows the definition of a function.

Thus , the answer is : Yes , is a function.