Question

Which of the following relations is a function?

A.
{(7,-2), (9,-1), (3,-2), (9,5)}
B.
{(8,4), (6,3), (6,2), (0,0)}
C. {(4, -1), (7,0), (6,0), (4,0)}
D. {(10,2), (5,3), (8,1), (3,2)}

Answer 1

keeping in mind that a function doesn't have any X-repeats, namely the x-values in the set aren't repeated, let's check the sets above.

Check the picture below.