[ f = (0, 2), (1, 5), (2, 7), (3, 9) ] and ( g = (2, 2), (5, 0), (7, 1), (9, 3) ). Find:

a) ( f ⋅ g )
b) ( g ⋅ f )
c) ( f ° g )
d) ( g ° f )