Answer with Step-by-step explanation:
A function is a map from a set A to another set B such that
the image of any point in a has a unique image in set B.
A = {(1, 2), (2, 3), (3, 4), (4, 5)}
It is a function since image of 1,2,3 and 4 is unique.
B = {(1, 2), (2, 1), (3, 0), (4, -1)}
It is a function since image of 1,2,3 and 4 is unique.
C = {(-1, 3), (0, 3), (1, 3), (2, 3)}
It is a function since image of -1,0,1 and 2 is unique.
D = {(1, 1), (1, 2), (1, 3), (1, 4)}
It is not a function since image of 1 is not unique.
E = {(6, 2), (7, 3), (6, -1), (5, 4)}
It is not a function since image of 6 is not unique.
Hence, sets that are not functions are:
D = {(1, 1), (1, 2), (1, 3), (1, 4)}
E = {(6, 2), (7, 3), (6, -1), (5, 4)}
