Let A = {1, 2, 3, 4}, B = {1, 5, 9, 11, 15, 16} and f = {(1, 5), (2, 9), (3, 1), (4, 5), (2, 11)}. Are the following true?       (3 marks)

(i) f is a relation from A to B (ii) f is a function from A to B.

Justify your answer in each case.