If A = {1, 3, 5} and B= {2, 4, -1} then find A×B and B×A . Find the number of elements in A×B and B×A.
Solution:
Given,
A×B = {(1, 2), (1, 4), (1, -1), (3, 2), (3, 4), (3, -1), (5, 2), (5, 4), (5, -1)}
B×A= {(2, 1), (2, 3), (2, 5), (4, 1), (4,3), (4, 5), (-1, 1), (-1, 3), (-1, 5)}
Therefore, n(A×B) = 9 and n(B×A)= 9
Exercise: 1.2