If A = {x : x ∈ ℕ, x is a square root of 36}, what is A?
Answer and explanation
Correct answer: {6}
The numbers whose square is 36 are 6 and −6, because 6² = 36 and (−6)² = 36. However, the set specifically restricts x to natural numbers, and under the standard school convention natural numbers are positive counting numbers. Therefore −6 is excluded, while 6 is included. Hence A contains exactly one element and A = {6}.
Frequently asked questions
What is the correct answer to this question?
{6}
Why is this the correct answer?
The numbers whose square is 36 are 6 and −6, because 6² = 36 and (−6)² = 36. However, the set specifically restricts x to natural numbers, and under the standard school convention natural numbers are positive counting numbers. Therefore −6 is excluded, while 6 is included. Hence A contains exactly one element and A = {6}.
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.
