Respuesta :

Function:

A function is a relation in which each input (x) has only one output (y).

If any one input (x) has more than one output (y) then it is not a function.

As you can see from the given table, the value of (a) must be anything other than (2)

So we can set a value of 4 for (a)

Now if you notice, each input will have exactly one output value so the criteria of a function is satisfied.

So, the answer is 4