If the nth term of a sequence is \(a_n=5-4n\), which of the following statements is correct?
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Answer and explanation
Correct answer: It is an AP with first term \(1\) and common difference \(-4\).
The nth-term form of an AP is \(a_n=a+(n-1)d\). Here, \(5-4n=1+(n-1)(-4)\), so the first term is \(1\) and the common difference is \(-4\). A negative difference still forms an AP. Exam tip: put \(n=1\) to find the first term quickly.
Frequently asked questions
What is the correct answer to this question?
It is an AP with first term \(1\) and common difference \(-4\).
Why is this the correct answer?
The nth-term form of an AP is \(a_n=a+(n-1)d\). Here, \(5-4n=1+(n-1)(-4)\), so the first term is \(1\) and the common difference is \(-4\). A negative difference still forms an AP. Exam tip: put \(n=1\) to find the first term quickly.
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.
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