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
科目:

选择章节

总题量:299 选择本页全部试题
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知正项等比数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),\(S_{3}=7a_{1}\),且\(a_{1}\),\(a_{2}+2\),\(a_{3}\)成等差数列.
    \((1)\)求\(\{a_{n}\}\)的通项公式;
    \((2)\)若\(b_{n}=\begin{cases}{a_{n},n\text{为奇数}}\\ {n,n\text{为偶数}}\end{cases}\),求数列\(\{b_{n}\}\)的前\(2n\)项和\(T_{2n}.\)
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知数列\(\{a_{n}\}\)前\(n\)项和为\(S_{n}\),若\(2S_{n}=(n+1)a_{n}\),且\(a_{1}>1\),\(a_{2}-1\),\(a_{4}-2\),\(a_{6}\)成等比数列.
    \((1)\)求数列\(\{a_{n}\}\)的通项公式;
    \((2)\)设\(b_{n}=\dfrac{4}{a_{n}a_{n+1}}+2^{-a_{n}}\),数列\(\{b_{n}\}\)的前\(n\)项和为\(T_{n}\),求证:\(T_{n}< \dfrac {4}{3}.\)
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知等比数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),且\(a_{n+1}=2S_{n}+1(n\in N_{+}).\)
    \((1)\)求数列\(\{a_{n}\}\)的通项公式;
    \((2)\)若数列\(\{b_{n}\}\)满足\(a_{n}=3^{b_{n}-1}\),求数列\(\{\dfrac{b_{n}}{a_{n}}\}\)的前\(n\)项和\(T_{n}.\)
  • 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:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知等差数列\(\{a_{n}\}\)中,\(a_{1}+a_{5}=16\),\(a_{6}=17.\)
    \((1)\)求数列\(\{a_{n}\}\)的通项公式;
    \((2)\{b_{n}\}\)为正项数列,若_____,求数列\(\{a_{n}\boldsymbol{⋅}b_{n}\}\)的前\(n\)项和\(T_{n}.\)
    请在①\(\{b_{n}\}\)的前\(n\)项和为\(S_{n}\),且\(S_{1}=2\),\(b_{n+1}=S_{n}+2\),②\(\{b_{n}\}\)为等比数列,且\(b_{1}=2\),\(b_{2}+b_{3}\)是\(b_{3}\)与\(b_{4}\)的等差中项,③\(\{b_{n}\}\)为等比数列,且\(b_{6}=b_{1}b_{5}=64\),这三个条件中任选一个,补充在上面的横线上,并完成解答.
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    设公比\(q>1\)的等比数列\(\{a_{n}\}\)满足:\(a_{2}+a_{3}+a_{4}=39\),且\(a_{3}+6\)是\(a_{2}\)与\(a_{4}\)的等差中项.
    \((1)\)求数列\(\{a_{n}\}\)通项公式;
    \((2)\)求数列\(\{(-1)^{n-1}\boldsymbol{⋅}a_{n}\}\)的前\(n\)项和\(S_{n}.\)
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    在正项数列\(\{a_{n}\}\)中,\(a_{1}=10\),\(a_{n}^{2}=a_{n+1}\),\(n\in N*.\)
    \((1)\)求数列\(\{a_{n}\}\)的通项公式;
    \((2)\)若\(b_{n}=a_{n}^{2n-1}\),\(n\in N*\),求数列\(\{b_{n}\}\)的前\(n\)项积\(T_{n}.\)
  • 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\(a_{1}=1\),\(a_{n+1}=\begin{cases}{2a_{n},n\text{为奇数}}\\ {a_{n}+3,n\text{为偶数}}\end{cases}.\)
    \((1)\)从下面两个条件中选一个,写出\(b_{1}\),\(b_{2}\),并求数列\(\{b_{n}\}\)的通项公式;
    ①\(b_{n}=a_{2n-1}+3\);
    ②\(b_{n}=a_{2n+1}-a_{2n-1}.\)
    \((2)\)求数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}.\)
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知数列\(\{a_{n}\}\),\(a_{1}=1\),\(∀n\in N_{+}\),\(a_{n+1}=2a_{n}+1.\)
    \((1)\)求证:\(\{a_{n}+1\}\)是等比数列;
    \((2)\)设\(b_{n}=2^{n}a_{n}(∀n\in N_{+})\),求数列\(\{b_{n}\}\)的前\(n\)项和.
  • 题型:解答题 题类:月考试卷 难易度:较易

    年份:2021

    已知\(S_{n}\)是等差数列\(\{a_{n}\}\)的前\(n\)项和,\(a_{2}=1.\)从下面的两个条件中任选其中一个:①\(2a_{5}-a_{3}=11\);②\(S_{4}=8\),求解下列问题:
    \((Ⅰ)\)求数列\(\{a_{n}\}\)的通项公式;
    \((Ⅱ)\)设\(b_{n}=\dfrac{1}{S_{n+2}}\),数列\(\{b_{n}\}\)的前\(n\)项和为\(T_{n}\),证明:\(T_{n}< \dfrac {3}{4}.\)