Question

Select the sets that are not functions.

A = {(1, 2), (2, 3), (3, 4), (4, 5)}
B = {(1, 2), (2, 1), (3, 0), (4, -1)}
C = [(-1, 3), (0, 3), (1, 3), (2, 3)}
D = {(1, 1), (1, 2), (1, 3), (1, 4);
E = {(6,2), (7,3), (6,-1), (5,4)}

Answer 1

D,E are not functions

Explanation:

A function is a relation in which every input has not more than one output.But the output of the inputs may be same.Here in D the input 1 has 4 different outputs as 1,2,3,4.So its not a function.Similarly in E 6 has 2 outputs as 2 and -1.For remaining sets the inputs has only one output.so they are functions.