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            • 1.

              已知数列\(\left\{ {{a}_{n}} \right\}\)的通项公式\({{a}_{n}}=-n+t\),数列\(\left\{ {{b}_{n}} \right\}\)的通项公式\({{b}_{n}}={{2}^{n}}\),设数列\(\left\{ {{c}_{n}} \right\}\)满足\({{c}_{n}}=\dfrac{{{a}_{n}}+{{b}_{n}}}{2}+\dfrac{\left| {{a}_{n}}-{{b}_{n}} \right|}{2}\),且\({{c}_{n}}\geqslant {{c}_{3}}\left( n\in {{N}^{{*}}} \right)\),则实数\(t\)的取值范围是________________

            • 2. 已知数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),且\(a_{1}=1\),\(a_{n+1}= \dfrac {1}{2}S_{n}\),则\(a_{5}=(\)  \()\)
              A.\( \dfrac {1}{16}\)
              B.\( \dfrac {1}{8}\)
              C.\( \dfrac {27}{16}\)
              D.\( \dfrac {81}{16}\)
            • 3.

              已知数列\(\{{{a}_{n}}\}\)中,\({{a}_{1}}=1\),\({{a}_{n+1}}=c+\dfrac{1}{{{a}_{n}}}\),且\(1\leqslant {{a}_{n}}\leqslant 4\),则\(c\)的取值范围是___\(.\) 

            • 4.

              已知数列\(\{a_{n}\}\)是递增数列,且对任意\(n∈N^{*}\)都有\(a_{n}=n^{2}+bn\)成立,则实数\(b\)的取值范围\((\)    \()\)

              A.\((-\dfrac{7}{2},+\infty )\)
              B.\((0,+∞)\)
              C.\((-2,+∞)\)
              D.\((-3,+∞)\)
            • 5. 已知数列\(\left\{ {{a}_{n}} \right\}\)的前\(n\)项和为\(S_{n}\),且\({{a}_{1}}=2\),对任意\(n\geqslant 2,n\in {{N}^{*}}\),点\(\left({a}_{n},{S}_{n-1}\right) \)都在函数\(f(x)=x-2\)的图象上.
              \((1)\)求数列\(\left\{ {{a}_{n}} \right\}\)的通项公式;

              \((2)\)设\({{b}_{n}}=\dfrac{2}{{{\log }_{2}}{{a}_{4n-3}}{{\log }_{2}}{{a}_{4n+1}}}\),\({{T}_{n}}\)是数列\(\left\{ {{b}_{n}} \right\}\)的前\(n\)项和,是否存在最大的正整数\(k\),使得对于任意的正整数\(n\),有\({{T}_{n}} > \dfrac{k}{20}\)恒成立?若存在,求出\(k\)的值;若不存在,说明理由.
            • 6. 下面是关于公差\(d > 0\)的等差数列\(\{a_{n}\}\)的四个命题:
              \((1)\)数列\(\{a_{n}\}\)是递增数列;\((2)\)数列\(\{na_{n}\}\)是递增数列;
              \((3)\)数列\(\left\{ \dfrac{{a}_{n}}{n}\right\} \)是递减数列;\((4)\)数列\(\{a_{n}+3nd\}\)是递增数列.
              其中的真命题的个数为\((\)  \()\)
              A.\(0\)              
              B.\(1\)              
              C.\(2\)              
              D.\(3\)
            • 7.

              已知函数\(f(x)=\dfrac{x}{\sqrt{1+{{x}^{2}}}}(x > 0)\),数列\(\left\{ {{a}_{n}} \right\}\)满足\({{a}_{1}}=f(x)\),\({{a}_{n+1}}=f({{a}_{n}})\)

              \((\)Ⅰ\()\)求\({{a}_{2}}\),\({{a}_{3}}\),\({{a}_{4}}\);

              \((\)Ⅱ\()\)猜想数列\(\left\{ {{a}_{n}} \right\}\)的通项,并予以证明。

            • 8.

              已知数列\(\left\{ {{a}_{n}} \right\}\)满足\({{a}_{1}}=60\),\({{a}_{n+1}}-{{a}_{n}}=2n(n\in {{\text{N} }^{*}})\),则\(\dfrac{{{a}_{n}}}{n}\)的最小值为_______.

            • 9. 已知数列\(\{a_{n}\}\)的前\(n\)项和\(s_{n}=32n-n^{2}+1\),
              \((1)\)求数列\(\{a_{n}\}\)的通项公式;
              \((2)\)求数列\(\{a_{n}\}\)的前多少项和最大.
            • 10.

              已知数列\(\left\{ {{a}_{n}} \right\}\),\({{a}_{n}} > 0\),其前\(n\)项和\({{S}_{n}}\)满足\({{S}_{n}}=2{{a}_{n}}-{{2}^{n+1}}\),其中\(n\in N*\).

              \((\)Ⅰ\()\)设\({{b}_{n}}=\dfrac{{{a}_{n}}}{{{2}^{n}}}\),证明:数列\(\left\{ {{b}_{n}} \right\}\)是等差数列;

              \((\)Ⅱ\()\)设\({{c}_{n}}={{b}_{n}}\cdot {{2}^{-n}}\),\({{T}_{n}}\)为数列\(\left\{ {{c}_{n}} \right\}\)的前\(n\)项和,求证:\({{T}_{n}} < 3\);

              \((\)Ⅲ\()\)设\({{d}_{n}}={{4}^{n}}+{{(-1)}^{n-1}}\lambda \cdot {{2}^{{{b}_{n}}}}(\lambda \)为非零整数,\(n\in N*)\),试确定\(\lambda \)的值,使得对任意\(n\in N*\),都有\({{d}_{n+1}} > {{d}_{n}}\)成立.

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