If A = {x : x² = 4} and B = {-2, 2}, which of the following is correct?
Answer and explanation
Correct answer: A = B
Solving x² = 4 over the real numbers gives x = 2 or x = -2. Hence A = {-2, 2}. Since B contains exactly the same two elements, A and B are equal, so A = B. Neither is a proper subset of the other. Option D is incorrect because it omits the valid solution -2. Equality of sets depends on having exactly the same elements, regardless of their order.
Frequently asked questions
What is the correct answer to this question?
A = B
Why is this the correct answer?
Solving x² = 4 over the real numbers gives x = 2 or x = -2. Hence A = {-2, 2}. Since B contains exactly the same two elements, A and B are equal, so A = B. Neither is a proper subset of the other. Option D is incorrect because it omits the valid solution -2. Equality of sets depends on having exactly the same elements, regardless of their order.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Equal sets and Subsets.
