Question
Question: Let a relation R be defined by R = {(4, 5); (1, 4); (4, 6); (7, 6); (3, 7)} then \(R ^ { - 1 } o R\...
Let a relation R be defined by R = {(4, 5); (1, 4); (4, 6);
(7, 6); (3, 7)} then R−1oR is
A
{(1, 1), (4, 4), (4, 7), (7, 4), (7, 7), (3, 3)}
B
{(1, 1), (4, 4), (7, 7), (3, 3)}
C
{(1, 5), (1, 6), (3, 6)}
D
None of these
Answer
{(1, 1), (4, 4), (4, 7), (7, 4), (7, 7), (3, 3)}
Explanation
Solution
We first find R−1 we have
R−1={(5,4);(4,1);(6,4);(6,7);(7,3)} we now obtain the
elements of R−1oR we first pick the element of R and then of R−1 . Since (4,5)∈R and (5,4)∈R−1 , we have (4,4)∈R−1oR
Similarly,
(4,6)∈R,(6,4)∈R−1⇒(4,4)∈R−1oR (4,6)∈R,(6,7)∈R−1⇒(4,7)∈R−1oR (7,6)∈R,(6,4)∈R−1⇒(7,4)∈R−1oR (7,6)∈R,(6,7)∈R−1⇒(7,7)∈R−1oR
Hence R−1oR={(1, 1); (4, 4); (4, 7); (7 , 4), (7, 7); (3, 3)}..