If (a_n=n^2-3n), what is the value of (a_7)?
Answer and explanation
Correct answer: 28
Given \(a_n=n^2-3n\). Substituting \(n=7\), \(a_7=7^2-3(7)=49-21=28\). Therefore, 28 is the correct option. A value such as 24 can result from an error while calculating \(7^2\) or \(3\times7\). Exam tip: To find a particular term, substitute the given term number carefully for \(n\) in the formula.
Frequently asked questions
What is the correct answer to this question?
28
Why is this the correct answer?
Given \(a_n=n^2-3n\). Substituting \(n=7\), \(a_7=7^2-3(7)=49-21=28\). Therefore, 28 is the correct option. A value such as 24 can result from an error while calculating \(7^2\) or \(3\times7\). Exam tip: To find a particular term, substitute the given term number carefully for \(n\) in the formula.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Sequences and Progressions. Topic: Explicit or general rule.
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