Examples: a. {(1, 1), (2, 3), (3, 5), (4, 7), (5, 9)} domain (x): {1, 2, 3, 4, 5) range (y): {1, 3, 5, 7, 9) function b. {(3, -1), (0, 0), (-3, 0) (-6, 2)} domain (x): {3, 0, -3, -6} range (y): {-1, 0, 2} function c. {(2, 5), (2, 2), (2, −1), (2,0)} domain (x): {2} range (y): {5, 2, -1, 0} Not a function