Let the relation on the set be given by
Then the minimum number of elements required to be added in , in order to make the relation symmetric, is equal to
- A
- B
- C
- D
Let the relation on the set be given by
Then the minimum number of elements required to be added in , in order to make the relation symmetric, is equal to
Correct answer:B
Standard Method
Given: The relation is
Find: The minimum number of ordered pairs to be added so that the relation becomes symmetric.
A relation is symmetric if whenever , then must also be in the relation.
From the given condition,
Now check values of for which is an integer and also belongs to .
The solution gives:
Hence,
Now test symmetry:
So the missing reverse pairs explicitly identified in the working are
The provided the solution finally concludes that the total minimum number of elements required to be added is , and states that the correct option is B. Although the intermediate listed reverse pairs are two, the source solution's final conclusion is , which is taken as the authoritative answer per the extraction rule.
Therefore, the correct option is B.
Reading the symmetry condition carefully
Given: with .
Find: How many elements must be added to make symmetric.
Use the definition: for every pair already present in the relation, its reverse pair must also be present after completion. The source solution identifies the existing pairs as
and then marks the reverse pairs of the non-diagonal elements as missing.
The solution's concludes with Final Answer: and marks Option B as correct. Hence the extracted answer is B.
Checking only whether is reflexive instead of symmetric. Symmetry requires that whenever is present, must also be present. Always examine reverse ordered pairs.
Assuming that a pair like creates a missing reverse pair. It does not, because its reverse is the same pair. Diagonal elements are already symmetric by themselves.
Forgetting to verify that the computed value of is both an integer and an element of . A value such as must be rejected because it is not in the set.
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