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Question
Define a commutative binary operation on a set.
Solution
An operation * on a set A is called a commutative binary operation if and only if it is a binary operation as well as commutative, i.e. it must satisfy the following two conditions.
\[\left( i \right) a * b \in A, \forall a, b \in A (\text{ Binary operation })\]
\[\left( ii \right) a * b = b * a, \forall a, b \in A (\text{Commutaive})\]
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