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
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  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知正项数列\(\{a_{n}\}\)满足\(a_{1}=1\),\(a_{2}=2\),且对任意的正整数\(n\),\(1+a_{n+1}^{2}\)是\(a_{n}^{2}\)和\(a_{n+2}^{2}\)的等差中项.
    \((1)\)证明:\(\{a_{n+1}^{2}-a_{n}^{2}\}\)是等差数列,并求\(\{a_{n}\}\)的通项公式;
    \((2)\)若\(b_{n}-b_{n-1}=a_{n}\),且\(b_{1}=a_{1}\),求数列\(\{b_{n}\}\)的通项公式.
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知正项数列\(\{a_{n}\}\)满足\(a_{1}=3\),\(\dfrac{a_{n}+a_{n-1}}{a_{n}-a_{n-1}}=2n(n\in N^{*},n\geqslant 2).\)
    \((Ⅰ)\)写出\(a_{2}\),\(a_{3}\),并证明数列\(\{a_{n}\}\)是等差数列;
    \((Ⅱ)\)设数列\(\{b_{n}\}\)满足\(b_{1}=2\),\(b_{n+1}b_{n}-b_{n}^{2}=a_{n}(n\in N^{*})\),求证:\(b_{1}+b_{2}+b_{3}+⋯+b_{n}\geqslant\dfrac{n(n+3)}{2}.\)
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),\(a_{1}=1\),\(S_{n+1}=4a_{n}+2(n\in N*).\)
    \((1)\)设\(b_{n}=a_{n+1}-2a_{n}\),求证:\(\{b_{n}\}\)是等比数列;
    \((2)\)设\(c_{n}=\dfrac{a_{n}}{2^{n-2}}\),求证:\(\{c_{n}\}\)是等差数列.
  • 题型:选择题 题类:月考试卷 难易度:较易

    年份:2021

    在等差数列\(\{a_{n}\}\)中,\(3(a_{3}+a_{5})+2({a}_{8}+a_{9}+a_{13})=24\),则此数列前\(13\)项的和是\((\quad)\)

    A. B. C. D.        
  • 题型:选择题 题类:月考试卷 难易度:较易

    年份:2021

    已知数列\(\{a_{n}\}\)满足\(a_{n}-a_{n-1}=2(n\geqslant 2)\),且\(a_{1}\),\(a_{3}\),\(a_{4}\)成等比数列,则数列\(\{a_{n}\}\)的通项公式为\((\quad)\)
    A.\(a_{n}=2n\) B.\(a_{n}=2n+10\) C.\(a_{n}=2n-10\) D.\(a_{n}=2n+4\)
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知数列\(\{a_{n}\}\)满足\(3a_{n+1}=a_{n}+\dfrac{1}{3^{n}},a_{1}=\dfrac{2}{3}\),设\(b_{n}=3^{n}\cdot a_{n}.\)
    \((1)\)证明:数列\(\{b_{n}\}\)为等差数列;
    \((2)\)求数列\(\{a_{n}\}\)的前\(n\)项和\(S_{n}.\)
  • 题型:填空题 题类:月考试卷 难易度:较易

    年份:2021

    已知两个等差数列\(\left\{{{a}_{n}}\right\}\)和\(\left\{{{b}_{n}}\right\}\)的前\(n\)项和分别为\({{S}_{n}}\),\({{T}_{n}}\),且\(\dfrac{{{S}_{n}}}{{{T}_{n}}}=\dfrac{5n}{n+5}\),则\(\dfrac{{{a}_{10}}+{{a}_{11}}}{{{b}_{8}}+{{b}_{13}}}=\)__________.

  • 题型:选择题 题类:月考试卷 难易度:较易

    年份:2021

    设数列\(\{a_{n}\}\)是等差数列,\(a_{2}=-6\),\(a_{8}=6\),\(S_{n}\)是数列\(\{a_{n}\}\)的前\(n\)项和,则\((\quad)\)
    A.\(S_{4}< S_{5}\) B.\(S_{4}=S_{5}\) C.\(S_{6}< S_{5}\) D.\(S_{6}=S_{5}\)
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知数列\(\{a_{n}\}\)的首项\(a_{1}=2\),且\(a_{n+1}=\dfrac{2a_{n}-1}{a_{n}}.\)
    \((1)\)证明:数列\(\{\dfrac{1}{a_{n}-1}\}\)为等差数列.
    \((2)\)已知\(b_{n}=\lg a_{n}\),数列\(\{b_{n}\}\)的前\(n\)项和为\(S_{n}\),若\(S_{m}>2\),求整数\(m\)的最小值.
  • 题型:选择题 题类:月考试卷 难易度:较易

    年份:2021

    设\(\{a_{n}\}\)是等差数列,从\(\{a_{1},a_{2},a_{3},\)…,\(a_{10}\}\)中任取\(3\)个不同的数,使这三个数仍成等差数列,则这样不同的等差数列最多有\((\quad)\)
    A.\(40\) B.\(10\) C.\(22\) D.\(11\)