职教组卷基于海量职教高考试题库建立的在线组卷及学习系统
职教组卷
  • 题型:解答题 题类:期中考试 难易度:较易

    等比数列\(\{a_{n}\}\)中,首项\(a_{1}=\dfrac{1}{3}\),公比\(q>0\),\(q≠1\),且\(a_{1}\),\(5a_{3}\),\(9a_{5}\)成等差数列.
    \((Ⅰ)\)求\(\{a_{n}\}\)的通项公式;
    \((Ⅱ)\)令\(b_{n}=\log_{3}\dfrac{1}{a_{n}}\),求数列\(\{\dfrac{1}{b_{n}b_{n+1}}\}\)的前\(n\)项和为\(T_{n}.\)
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