Question

Select the correct answer.
Which relation is a function?
A.
{(2, 3), (1, 5), (2, 7)}
B.
{(-1, 5), (-2, 6), (-3, 7)}
C.
{(11, 9), (11, 5), (9, 3)}
D.
{(3, 8), (0, 8), (3, -2)}

Answer 1

B. Each first coordinate (-1, -2, -3) is used only once, so the relation is a function.