Which is the correct rule for the sequence (8,17,28,41,\ldots)?
Answer and explanation
Correct answer: \(a_n=n^2+6n+1\)
Substituting \(n=1,2,3,4\) into \(a_n=n^2+6n+1\) gives \(8,17,28,41\), respectively. Therefore, option A is correct. In option B, the term for \(n=2\) is \(18\), not the given second term \(17\). Exam tip: Verify a proposed sequence rule by substituting at least the first two or three values of \(n\).
Frequently asked questions
What is the correct answer to this question?
\(a_n=n^2+6n+1\)
Why is this the correct answer?
Substituting \(n=1,2,3,4\) into \(a_n=n^2+6n+1\) gives \(8,17,28,41\), respectively. Therefore, option A is correct. In option B, the term for \(n=2\) is \(18\), not the given second term \(17\). Exam tip: Verify a proposed sequence rule by substituting at least the first two or three values of \(n\).
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Sequences and Progressions. Topic: Explicit or general rule.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
