What is the type of the set {x ∈ ℤ : x² = 2}?
Answer and explanation
Correct answer: Empty set
Solving x² = 2 over the real numbers gives x = √2 and x = −√2. Neither value is an integer, because √2 is irrational. Since the domain in the set-builder notation is ℤ, neither real solution is allowed. Thus no integer satisfies the condition, so the set is empty and option A is correct.
Frequently asked questions
What is the correct answer to this question?
Empty set
Why is this the correct answer?
Solving x² = 2 over the real numbers gives x = √2 and x = −√2. Neither value is an integer, because √2 is irrational. Since the domain in the set-builder notation is ℤ, neither real solution is allowed. Thus no integer satisfies the condition, so the set is empty and option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: The Empty Set, Finite and Infinite Sets, Equal Sets.