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

  • 题型:选择题 题类:期中考试 难易度:较易

    年份:2020

    已知递减的等差数列\(\{a _{n} \}\)满足\({{a}_{1}}^{2} = {{a}_{9}}^{2} \),则数列\(\{a _{n} \}\)的前\(n\)项和\(S _{n}\)取最大值时,\(n= (\:\:\:\:)\)
    A.\(3\) B.\(4\) C.\(4\)或\(5\) D.\(5\)或\(6\)
  • 题型:选择题 题类:期中考试 难易度:较易

    年份:2020

    设等差数列\(\{a _{n} \}\)的前\(n\)项和为\(S _{n}\),且满足\(S _{2020} > 0\),\(S _{2021} < 0\),对任意正整数\(n\),都有\(|a _{n} |\geqslant |a _{k} |\),则\(k\)的值为\((\:\:\:\:)\)
    A.\(1009\) B.\(1010\) C.\(1011\) D.\(1012\)
  • 题型:选择题 题类:期中考试 难易度:较易

    年份:2020

    已知递减的等差数列\(\{a _{n} \}\)满足\(|a _{1} |=|a _{9} |\),则数列\(\{a _{n} \}\)的前\(n\)项和最大时,\(n= (\:\:\:\:)\)
    A.\(4\)或\(5\) B.\(5\)或\(6\) C.\(4\) D.\(5\)
  • 题型:选择题 题类:期中考试 难易度:易

    年份:2020

    已知公差不为\(0\)的等差数列\(\{a _{n} \}\)的前\(n\)项和为\(S _{n}\),若\(a _{m} =8\),\(S _{9} =72\),则\(m= (\:\:\:\:)\)
    A.\(4\) B.\(5\) C.\(6\) D.\(7\)
  • 题型:选择题 题类:期中考试 难易度:易

    年份:2020

    等差数列\(\{a _{n} \}\)的前\(n\)项和为\(S _{n}\),若\(S _{8} =2020\),则\(a _{3} +4a _{4} +a _{8}\)等于\((\:\:\:\:)\)
    A.\(2020\) B.\(1525\) C.\(1515\) D.\(2015\)
  • 题型:选择题 题类:期中考试 难易度:易

    年份:2020

    已知等差数列\(\{a _{n} \}\)中,\(a _{3}\),\(a _{5}\)是函数\(f(x)=x ^{2} -14x+45\)的两个零点,则\(\{a _{n} \}\)的前\(7\)项和为\((\:\:\:\:)\)
    A.\(36\) B.\(42\) C.\(49\) D.\(32\)
  • 题型:选择题 题类:期中考试 难易度:较易

    年份:2020

    记\(S _{n}\)为等差数列\(\{a _{n} \}\)的前\(n\)项和.若\(a _{6} +a _{7} =24\),\(S _{8} =48\),则\(\{a _{n} \}\)的公差为\((\:\:\:\:)\)
    A.\(1\) B.\(3\) C.\(4\) D.\(8\)
  • 题型:选择题 题类:期中考试 难易度:中档

    年份:2020

    若等差数列\(\left\{ {{a}_{n}} \right\}\)的前\(n\)项和为\({{S}_{n}}\),\(n\in {{N}^{*}}\),\({{S}_{12}} > 0\),\({{S}_{13}} < 0\),则\({{S}_{n}}\)的最大值为\((\)   \()\)
    A.\({{S}_{5}}\) B.\({{S}_{6}}\) C.\({{S}_{7}}\) D.\({{S}_{12}}\)
  • 题型:选择题 题类:期中考试 难易度:易

    年份:2020

    已知等差数列\(\{a _{n} \}\)的前\(n\)项和为\(S _{n}\),\(S _{4} =7a _{1}\),则\( \dfrac {a_{5}}{a_{2}} = (\:\:\:\:)\)
    A.\(2\) B.\(3\) C.\( \dfrac {3}{2}\) D.\( \dfrac {5}{3}\)
  • 题型:选择题 题类:期中考试 难易度:较易

    年份:2020

    已知\(\{a _{n} \}\)是等差数列,且\(a _{1} +a _{2} =4\),\(a _{8} +a _{9} =6\),则这个数列的前\(9\)项和等于\((\:\:\:\:)\)
    A.\(45\) B.\( \dfrac {45}{2}\) C.\(55\) D.\( \dfrac {55}{2}\)