Question

Select the relations that are functions.

{(a, 1), (b, 1), (c, 1)}
{(a, a), (a, b), (a, c)}
{(1, a), (2, a), (3, a)}
{(a, a), (b, b), (c, c)}

Answer 1

multiple choice

Answer 2

a function can have at most one value for a single input