If (a_n=12-3n), which will be the first negative term?
Answer and explanation
Correct answer: 5th term
For a term to be negative, \(12-3n<0\). Thus \(3n>12\), so \(n>4\). The smallest natural value of \(n\) is 5; hence \(a_5=12-3(5)=-3\) is the first negative term. Note that \(a_4=0\), which is not negative. Exam tip: For the “first” term, choose the smallest positive integer satisfying the inequality.
Frequently asked questions
What is the correct answer to this question?
5th term
Why is this the correct answer?
For a term to be negative, \(12-3n<0\). Thus \(3n>12\), so \(n>4\). The smallest natural value of \(n\) is 5; hence \(a_5=12-3(5)=-3\) is the first negative term. Note that \(a_4=0\), which is not negative. Exam tip: For the “first” term, choose the smallest positive integer satisfying the inequality.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Sequences and Progressions. Topic: nth term.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
