Question

Which relation is a function ?

Answer 1

The correct option has been marked in the Figure below. A function
`f` from a set
`A` to a set
`B` is a relation that assigns to each element
`x` in the set
`A` exactly one element
`y` in the set
`B`. The set
`A` is the domain (also called the set of inputs) of the function and the set
`B` contains the range (also called the set of outputs).

For our correct option we have:

Set A, Domain:

Inputs: -2, 1, 0, 1, 2, 3

Set B, Range:

Outputs: -1, 0, 1, 2, 3

This is a function because this is a relation that assigns to each element
`x` in the set
`A` exactly one element
`y` in the set
`B`. So, the assignation is as follow:

• -2 (in x) matches to 0 (in y)
• -1 (in x) matches to 3 (in y)
• 0 (in x) matches to 2 (in y)
• 1 (in x) matches to -1 (in y)
• 2 (in x) matches to 0 (in y)
• 3 (in x) matches to 2 (in y)