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            • 1.

              等比数列\(\{\)\(a_{n}\)\(\}\)中,若\(a\)\({\,\!}_{7}+\)\(a\)\({\,\!}_{8}+\)\(a\)\({\,\!}_{9}+\)\(a\)\({\,\!}_{10}= \dfrac{15}{8}\),\(a\)\({\,\!}_{8}·\)\(a\)\({\,\!}_{9}=- \dfrac{9}{8}\),则\( \dfrac{1}{a_{7}}+ \dfrac{1}{a_{8}}+ \dfrac{1}{a_{9}}+ \dfrac{1}{a_{10}}=\)________.

            • 2.

              已知数列\(\{a_{n}\}\)是以\(a\)为首项,\(b\)为公比的等比数列,数列\(\{b_{n}\}\)满足\(b_{n}=1+a_{1}+a_{2}+…+a_{n}(n=1,2,…)\),数列\(\{c_{n}\}\)满足\(c_{n}=2+b_{1}+b_{2}+…+b_{n}(n=1,2,…)\),若\(\{c_{n}\}\)为等比数列,则\(a+b=\)

              A.\(\sqrt{2}\)
              B.\(3\)
              C.\(\sqrt{5}\)
              D.\(6\)
            • 3.

              在一次人才招聘会上,有\(A\)、\(B\)两家公司分别开出了它们的工资标准:\(A\)公司许诺第一年的月工资为\(1500\)元,以后每年月工资比上一年月工资增加\(230\)元;\(B\)公司许诺第一年的月工资为\(2000\)元,以后每年月工资在上一年月工资基础上递增\(5\%\)。若某人年初同时被\(A\)、\(B\)两家公司录取,问:

              \((1)\)若该人分别在\(A\)公司或\(B\)公司连续工作\(n\)年,则他在第\(n\)年的月工资收入分别是多少?

              \((2)\)该人打算连续在一家公司工作\(10\)年,仅从工资收入总量较多为应聘的标准,该人应选择哪家公司,为什么?\((1.{05}^{9}≈1.551, 1.{05}^{10}≈1.629, {{1.05}^{11}}\approx 1.710)\)

              \((3)\)在\(A\)公司工作比\(B\)公司工作的月工资收入最多可以多多少?\((\)精确到\(1\)元\()\),并说明理由。\((1.{05}^{16}≈2.183 \), \(1.{05}^{17}≈2.407 \), \(1.{05}^{18}≈2.407 \) ,\({{1.05}^{19}}\approx 2.527)\)

            • 4.

              \((1)\)曲线经过点\((2 \sqrt{2},1) \),其一条渐近线方程为\(y= \dfrac{1}{2}x \),该双曲线的标准方程为_________.

              \((2)D\)为\(\triangle ABC\)的边\(BC\)上一点,\(\overrightarrow{DC}=-2\overrightarrow{DB}\),过\(D\)点的直线分别交直线\(AB\)、\(AC\)于\(E\)、\(F\),若\(\overrightarrow{AE}=λ\overrightarrow{AB}\),\(\overrightarrow{AF}=μ\overrightarrow{AC}\),其中\(λ > 0\),\(μ > 0\),则\( \dfrac{2}{λ}+ \dfrac{1}{μ}=\)________.

              \((3)\)已知向量\(\overrightarrow{AB}\),\(\overrightarrow{AC}\),\(\overrightarrow{AD}\)满足\(\overrightarrow{AC}=\overrightarrow{AB}+\overrightarrow{AD}\),\(|\overrightarrow{AB}|=2\),\(|\overrightarrow{AD}|=1\),\(E\),\(F\)分别是线段\(BC\),\(CD\)的中点,若\(\overrightarrow{DE}·\overrightarrow{BF}=- \dfrac{5}{4}\),则向量\(\overrightarrow{AB}\)与\(\overrightarrow{AD}\)的夹角为________.

              \((4)\)已知数列\(\left\{ {{a}_{n}} \right\}\)中,\({{a}_{1}}=1,{{a}_{n+1}}=2{{a}_{n}}+n-1\left( n\in {{N}^{*}} \right)\),则其前\(n\)项和\({{S}_{n}}{=}\)_________.

            • 5.

              已知数列\(\left\{ {{a}_{n}} \right\}\)满足\({{a}_{1}}=\dfrac{3}{2},{{a}_{n+1}}=3{{a}_{n}}-1\left( n\in {{N}^{*}} \right).\)

              \((1)\)若数列\(\left\{ {{b}_{n}} \right\}\)满足\({{b}_{n}}={{a}_{n}}-\dfrac{1}{2}\),求证:\(\left\{ {{b}_{n}} \right\}\)是等比数列;

              \((2)\)求数列\(\left\{ {{a}_{n}} \right\}\)的\(n\)项和\({{S}_{n}}.\)

            • 6.

              已知数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),且\(a_{2}=8\),\(S_{n}=\dfrac{{{a}_{n+1}}}{2}-n-1\).

              \((1)\)求数列\(\{a_{n}\}\)的通项公式;

              \((2)\)求数列\(\left\{ \dfrac{2\times {{3}^{n}}}{{{a}_{n}}{{a}_{n+1}}} \right\}\)的前\(n\)项和\(T_{n}\).

            • 7.

              \(S_{n}\)是数列\(\{ a_{n}\}\)的前\(n\)项和,已知\({a}_{1}=1,{a}_{n+1}=2{S}_{n}+1(n∈{N}^{∗}) \)

              \((\)Ⅰ\()\)求数列\(\{ a_{n}\}\)的通项公式;
              \((\)Ⅱ\()\)\(\dfrac{b_{n}}{a_{n}}{=}3n{-}1\),求数列\(\{ b_{n}\}\)的前\(n\)项和\(T_{n}\)
            • 8.

              已知数列\(\{b_{n}\}\)满足\(b_{1}=1\),且\(16{b}_{n+1}={b}_{n}(n∈{N}^{*}) \),设数列\(\left\{ \sqrt{{b}_{n}}\right\} \)的前\(n\)项和是\(T_{n}\) .

              \((1)\)比较\({{T}_{n+1}}^{2} \)与\({T}_{n}·{T}_{n+2} \)的大小;

              \((2)\)若数列\(\{a_{n}\}\)的前\(n\)项和\(S_{n}=2n^{2}+2n+2\),数列\(\{c_{n}\}\)满足\(c_{n}=a_{n}+\log _{d}b\)n\((d > 0,d\neq 1) \),求\(d\)的取值范围,使得数列\(\{c_{n}\}\)是递增数列.

            • 9.

              已知数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),且\(a_{n}+S_{n}=An^{2}+Bn+1(A\neq 0)\).

              \((1)\)若\({{a}_{1}}=\dfrac{3}{2}\),\({{a}_{2}}=\dfrac{9}{4}\),证明数列\(\{a_{n}-n\}\)是等比数列,并求数列\(\{a_{n}\}\)的通项公式;

              \((2)\)若数列\(\{a_{n}\}\)是等差数列,求\(\dfrac{B-1}{A}\)的值.

            • 10.

              已知数列\({\)\(a_{n}\)\(}\)的前\(n\)项和为\(S_{n}\),且\(S_{n}\)\(=2\)\(a_{n}\)\(-2\),\(n\)\(∈N*\).

              \((1)\)求数列\({\)\(a_{n}\)\(}\)的通项公式;

              \((2)\)若数列\({\)\(b_{n}\)\(}\)满足\( \dfrac{1}{{a}_{n}} = \dfrac{{b}_{1}}{2+1}- \dfrac{{b}_{2}}{{2}^{2}+1}+ \dfrac{{b}_{3}}{{2}^{3}+1} -…+(-1)\)\({\,\!}^{n}\)\({\,\!}^{+1} \dfrac{{b}_{n}}{{2}^{n}+1} \),求数列\({\)\(b_{n}\)\(}\)的通项公式;

              \((3)\)在\((2)\)的条件下,设\(c_{n}\)\(=2\)\({\,\!}^{n}\)\(+\)\(l\)\(b_{n}\),问是否存在实数\(l\),使得数列\({\)\(c_{n}\)\(}\)是单调递增数列?若存在,求出\(l\)的取值范围;若不存在,请说明理由.

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