Question

Which of these are a function?

A. (4,5) (4,6) (2,7)
B. (2,1) (3,2) (9,1)
C. (3,4) (4,3) (3,3)
D. (1,2) (5,6) (4,6)

Answer 1

I'd say both b and d are functions. Niether one has a repeating x value which makes them functions.