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            • 1.

              在数列\(\left\{ {{a}_{n}} \right\}\)中,\({{a}_{{1}}}{+2}{{a}_{2}}+{{2}^{2}}{{a}_{3}}+\cdots +{{2}^{n-1}}{{a}_{n}}=(n\cdot {{2}^{n}}-{{2}^{n}}+1)\ t\)对任意\(n\in {{N}^{*}}\)成立,其中常数\(t > 0.\)若关于\(n\)的不等式\(\dfrac{1}{{{a}_{2}}}+\dfrac{1}{{{a}_{4}}}+\dfrac{1}{{{a}_{8}}}+\cdots +\dfrac{1}{{{a}_{{{2}^{n}}}}} > \dfrac{m}{{{a}_{1}}}\)的解集为\(\{n|n\geqslant 4,n\in {{N}^{*}}\}\),则实数\(m\)的取值范围是                   

            • 2.

              已知数列\(\{a_{n}\}\)的首项\(a_{1}=1\),前\(n\)项的和为\(S_{n}\),且满足\(2a_{n+1}+S_{n}=2(n∈N^{*})\),则满足\(\dfrac{1\mathrm{\ }001}{1\mathrm{\ }000} < \dfrac{S_{2n}}{S_{n}} < \dfrac{11}{10}\)的\(n\)的最大值为              \(.\) 

            • 3.

              \((1) \overset{⇀}{a}=\left(x,3\right)\;,\; \overset{⇀}{b}=\left(2\;,\;-1\right) \) ,若\( \overset{⇀}{a} \)与\( \overset{⇀}{b} \)的夹角为锐角,则\(x\)的范围是________________.

              \((2)\)数列\(\left\{{a}_{n}\right\} \)的通项公式为\({a}_{n}=2n-1+ \dfrac{1}{{2}^{n}} \),则数列\(\left\{{a}_{n}\right\} \) 的前\(n\)项和为________________.

              \((3)\) 若函数\(f\left(x\right)=\cos 2x+a\sin x \)在区间\(\left( \dfrac{π}{6}\;,\; \dfrac{π}{2}\right) \)上是减函数,则\(a\)的取值范围是________________.

              \((4)\) 设函数\(y=\begin{cases}-{x}^{3}+{x}^{2}\;,\;x < e \\ a\ln x\;,\;x\geqslant e\end{cases} \)的图象上存在两点 \(P\),\(Q\),使得\(∆POQ \)是以\(O\)为直角顶点的直角三角形\((\)其中\(O\)为坐标原点\()\),且斜边的中点恰好在\(y\)轴上,则实数\(a\)的取值范围是________________.

            • 4. 根据如图所示的程序框图,将输出的\(x\),\(y\)依次记为\(x_{1}\),\(x_{2}\),\(…\),\(x_{2016}\),\(y_{1}\),\(y_{2}\),\(…\),\(y_{2016}\).

                  \((1)\)求出数列\(\{x_{n}\}\),\(\{y_{n}\}\)的通项公式;

              \((2)\)求数列\(\{x_{n}+y_{n}\}(n\leqslant 2016)\)的前\(n\)项和\(S_{n}\).

            • 5.

              设等比数列\(\{{{a}_{n}}\}\)的公比\(q=2\),前\(n\)项和为\({{S}_{n}}\),则\(\dfrac{{{S}_{4}}}{{{a}_{2}}}=\)                     \((\)   \()\)

              A. \(2\)
              B.\(\dfrac{15}{2}\)
              C.\(4\)
              D.\(\dfrac{17}{2} \)
            • 6.

              在等比数列\(\{a_{n}\}\)中,公比\(q=2\),前\(87\)项和\(S_{87}=140\),则\(a_{3}+a_{6}+a_{9}+…+a_{87}\)等于\((\)  \()\)

              A.\( \dfrac{140}{3}\)
              B.\(60\)

              C.\(80\)                                                           
              D.\(160\)
            • 7.

              在等差数列\(\{{{a}_{n}}\}\)中,\({{a}_{2}}+{{a}_{7}}=-23\),\({{a}_{3}}+{{a}_{8}}=-29\).

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

              \((2)\)设数列\(\{{{a}_{n}}+{{b}_{n}}\}\)是首项为\(1\),公比为\(q\)的等比数列,求\(\{{{b}_{n}}\}\)的前\(n\)项和\({{S}_{n}}\).

            • 8.

              等比数列\(\{ a_{n}\}\)前四项和为\(1\),前\(8\)项和为\(17\),则它的公比为\(({  })\)

              A.\(2\)              
              B.\({-}2\)
              C.\(2\)或\({-}2\)
              D.\(2\)或\({-}1\)
            • 9.

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

              \((1)\)求数列\(\left\{ {{a}_{n}} \right\}\)的通项公式.

              \((2)\)设\({T}_{n}= \dfrac{1}{{a}_{1}}+ \dfrac{1}{{a}_{2}}+ \dfrac{1}{{a}_{3}}+⋯+ \dfrac{1}{{a}_{n}} \) ,是否存在正整数\(k\),使得当\(n\geqslant 3\)时,\({{T}_{n}}\in \left( \dfrac{k}{10},\dfrac{k+1}{10} \right)\) 如果存在,求出\(k\);如果不存在,请说明理由\(.\) 

            • 10.

              设数列\(1\),\(1+2\),\(1+2+2^{2}\),\(…\),\(1+2+2^{2}+…+2^{n-1}\),\(\cdots \)的前\(n\)项和为\(S_{n}\),则\(S_{10}=\)________.

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