If A = {x : x = n² − 1, n ∈ ℕ, 1 ≤ n ≤ 5}, which is the correct roster form of A?
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Answer and explanation
Correct answer: A = {0, 3, 8, 15, 24}
Because n is a natural number satisfying 1 ≤ n ≤ 5, substitute n = 1, 2, 3, 4, and 5 into x = n² − 1. The resulting values are 1² − 1 = 0, 2² − 1 = 3, 3² − 1 = 8, 4² − 1 = 15, and 5² − 1 = 24. Therefore the roster form is A = {0, 3, 8, 15, 24}, making option A correct.
Frequently asked questions
What is the correct answer to this question?
A = {0, 3, 8, 15, 24}
Why is this the correct answer?
Because n is a natural number satisfying 1 ≤ n ≤ 5, substitute n = 1, 2, 3, 4, and 5 into x = n² − 1. The resulting values are 1² − 1 = 0, 2² − 1 = 3, 3² − 1 = 8, 4² − 1 = 15, and 5² − 1 = 24. Therefore the roster form is A = {0, 3, 8, 15, 24}, making option A correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
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