If (a_n=3n^2+2), which term is (149)?
Answer and explanation
Correct answer: 7th
To obtain the value 149, set \(3n^2+2=149\). Then \(3n^2=147\), so \(n^2=49\) and \(n=7\). Since a term number must be a positive integer, 149 is the 7th term of the sequence. The 8th term is \(3(8)^2+2=194\), so it is not correct. Exam tip: equate the given value to \(a_n\) first, then solve for \(n\).
Frequently asked questions
What is the correct answer to this question?
7th
Why is this the correct answer?
To obtain the value 149, set \(3n^2+2=149\). Then \(3n^2=147\), so \(n^2=49\) and \(n=7\). Since a term number must be a positive integer, 149 is the 7th term of the sequence. The 8th term is \(3(8)^2+2=194\), so it is not correct. Exam tip: equate the given value to \(a_n\) first, then solve for \(n\).
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Sequences and Progressions. Topic: nth term.
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