If a_ 1 , a_ 2 , a_ 3 a_ n be an AP of non-zero terms then 1 a_ 1 a_ 2 + 1 a_ 2 a_ 3 + +…
Mathematics · JEE Main · NTA Exams — Progression and Series
If \(a_{1}, a_{2}, a_{3} \ldots a_{n}\) be an AP of non-zero terms then \(\frac{1}{a_{1} a_{2}}+\frac{1}{a_{2} a_{3}}+\ldots+\frac{1}{a_{n-1} a_{n}} \text { is }\)
- \(\frac{n}{a_{1} a_{n}}\)
- \(\frac{n(n-1)}{a_{1} a_{n}}\)
- \(\frac{n-1}{a_{1} a_{n}}\)
- None of these
Answer
(C) n-1 a_ 1 a_ n
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