If A = {1, 2, 3}, what is A − A?
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Answer and explanation
Correct answer: ∅
The difference A − A asks for elements that are in the first copy of A but not in the second copy. Since both copies are the same set, every element 1, 2, and 3 is removed by the subtraction. No element remains, so A − A = ∅. This is the general difference identity X − X = ∅.
Frequently asked questions
What is the correct answer to this question?
∅
Why is this the correct answer?
The difference A − A asks for elements that are in the first copy of A but not in the second copy. Since both copies are the same set, every element 1, 2, and 3 is removed by the subtraction. No element remains, so A − A = ∅. This is the general difference identity X − X = ∅.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).
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