Which of the following nth-term rules generates an arithmetic progression (AP)?
Advertisement
Answer and explanation
Correct answer: \(a_n=5n-2\)
For \(a_n=5n-2\), \(a_{n+1}-a_n=[5(n+1)-2]-(5n-2)=5\), which is constant; hence it is an AP. For \(n^2+1\), the differences change. Exam tip: test consecutive-term differences.
Frequently asked questions
What is the correct answer to this question?
\(a_n=5n-2\)
Why is this the correct answer?
For \(a_n=5n-2\), \(a_{n+1}-a_n=[5(n+1)-2]-(5n-2)=5\), which is constant; hence it is an AP. For \(n^2+1\), the differences change. Exam tip: test consecutive-term differences.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Arithmetic Progressions (AP). Topic: Finding the $n$th term of an AP.
Advertisement