优优班--学霸训练营 > 知识点挑题
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            • 1.
              在等差数列\(\{a_{n}\}\)中,\(a_{3}+a_{7}-a_{10}=-1\),\(a_{11}-a_{4}=21\),则\(a_{7}=(\)  \()\)
              A.\(7\)
              B.\(10\)
              C.\(20\)
              D.\(30\)
            • 2.
              在等差数列\(\{a_{n}\}\)中,已知\(a_{3}+a_{8}=6\),则\(3a_{2}+a_{16}\)的值为\((\)  \()\)
              A.\(24\)
              B.\(18\)
              C.\(16\)
              D.\(12\)
            • 3.
              已知等差数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),且\(2S_{3}-3S_{2}=15\),则数列\(\{a_{n}\}\)的公差为\((\)  \()\)
              A.\(3\)
              B.\(4\)
              C.\(5\)
              D.\(6\)
            • 4.
              已知\(\{a_{n}\}\)为等差数列,\(a_{3}+a_{8}=22\),\(a_{6}=8\),则\(a_{5}=\) ______ .
            • 5.
              已知\(a > b > 0\),且\(a\),\(b\),\(-2\)这三个数可适当排序后成等差数列,也可适当排序后成等比数列,则\(a+b=\) ______
            • 6.
              已知等差数列\(\{a_{n}\}\)的\(a_{6}+a_{7}+a_{8}=9\),则前\(13\)项的和为 ______ .
            • 7.
              在等差数列\(\{a_{n}\}\)中,\(a_{3}=-6\),\(a_{7}=a_{5}+4\),则\(a_{1}\)等于\((\)  \()\)
              A.\(-10\)
              B.\(-2\)
              C.\(2\)
              D.\(10\)
            • 8.
              等差数列\(\{a_{n}\}\)中,已知前\(15\)项的和\(S_{15}=90\),则\(a_{8}\)等于 ______ .
            • 9.
              已知等差数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),等比数列\(\{b_{n}\}\)的各项均为正数,公比为\(q\),且满足:\(a_{1}=3\),\(b_{1}=1\),\(b_{2}+S_{2}=12\),\(S_{2}=b_{2}q.\)
              \((1)\)求\(a_{n}\)与\(b_{n}\);
              \((2)\)设\(c_{n}=3b_{n}-2λ⋅ \dfrac {a_{n}}{3}(λ∈R)\),若数列\(\{c_{n}\}\)是递增数列,求\(λ\)的取值范围.
            • 10.
              已知数列\(\{a\) \(\}\)满足\(a= \dfrac {4}{3}\),\(a_{n+1}-1=a_{n}^{2}-a_{n}\) \((n∈N^{*})\),则\(m= \dfrac {1}{a_{1}}+ \dfrac {1}{a_{2}}+…+ \dfrac {1}{a_{2017}}\)的整数部分是\((\)  \()\)
              A.\(1\)
              B.\(2\)
              C.\(3\)
              D.\(4\)
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