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प्रश्न
Define identity element for a binary operation defined on a set.
उत्तर
Let * be a binary operation on a set A.
An element e is called an identity element in A with respect to * if and only if
\[a * e = e * a = a, \forall a \in A\]
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संबंधित प्रश्न
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(Hint: use the following table)
| * | 1 | 2 | 3 | 4 | 5 |
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| 5 | 1 | 1 | 1 | 1 | 5 |
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