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            • 1.

              设数列\(\{ a_{n}\}\)的前\(n\)项和为\(S_{n}\),且\(a_{1}{=}a_{2}{=}1\),\(\{ nS_{n}{+}(n{+}2)a_{n}\}\)为等差数列,则\(a_{n}{=}(\)  \()\)

              A.\(\dfrac{n}{2^{n{-}1}}\)
              B.\(\dfrac{n{+}1}{2^{n{-}1}{+}1}\)
              C.\(\dfrac{2n{-}1}{2^{n}{-}1}\)
              D.\(\dfrac{n{+}1}{2^{n{+}1}}\)
            • 2.

              已知在数列\(\{a_{n}\}\)中,\(a_{1}=1\),\(a_{n+1}=2a_{n}+n-1(n∈N*)\),则其前\(n\)项和\(S_{n}=\)________.

            • 3.

              等差数列\(\{a_{n}\}\)中,\(2a_{1}+3a_{2}=11\),\(2a_{3}+a_{6}-4\),其前\(n\)项和为\(S_{n}\).

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

              \((2)\)设数列\(\{b_{n}\}\)满足\({{b}_{n}}=\dfrac{1}{{{S}_{n+1}}-1}\),其前\(n\)项和为\(T_{n}\),求证:\({{T}_{n}} < \dfrac{3}{4}(n∈N^{*})\)

            • 4. 已知\(\{a_{n}\}\)是各项为正数的等比数列,\(\{b_{n}\}\)是等差数列,且\(a_{1}=b_{1}=1\),\(b_{2}+b_{3}=2a_{3}\),\(a_{5}-3b_{2}=7\).
              \((1)\)求\(\{a_{n}\}\)和\(\{b_{n}\}\)的通项公式;
              \((2)\)设\(c_{n}=a_{n}b_{n}\),\(n∈N^{*}\),求数列\(\{c_{n}\}\)的前\(n\)项和为\(S_{n}\).
            • 5.

              \(( 1 )\)已知向量\(\overrightarrow{a},\overrightarrow{b}\),满足\(\overrightarrow{a}=\left( 1,3 \right)\),\(\left( \overrightarrow{a}+\overrightarrow{b} \right)\bot \left( \overrightarrow{a}-\overrightarrow{b} \right)\),则\(\left| \overrightarrow{b} \right|=\)______.

              \(( 2 )\)已知实数\(x,y\)满足\(\begin{cases} & x\leqslant 3 \\ & x+y-3\geqslant 0 \\ & x-y+1\geqslant 0 \\ \end{cases}\),则\({{x}^{2}}+{{y}^{2}}\)的最小值是     

              \(( 3 )\)已知圆\(O:{{x}^{2}}+{{y}^{2}}=1.\)圆\({O}{{'}}\)与圆\(O\)关于直线\(x+y-2=0\)对称,则圆\({O}{{'}}\)的方程是__________.

              \(( 4 )\)已知数列\(\left\{ a{}_{n} \right\},\left\{ {{b}_{n}} \right\}\)满足\(b{}_{n}=\log {}_{2}a{}_{n},n\in {{N}^{*}}\),其中\(\left\{ {{b}_{n}} \right\}\)是等差数列,且\({{a}_{9}}{{a}_{2009}}=\dfrac{1}{4}.\)则\({{b}_{1}}+{{b}_{2}}+{{b}_{3}}+\cdot \cdot \cdot +{{b}_{2017}}=\)__________.

            • 6.

              设数列\(\left\{ {{a}_{n}} \right\}\)的前\(n\)项的和为\({{S}_{n}}\),点\((n,{{S}_{n}})\)在函数\(f(x)=2{{x}^{2}}\)的图象上,数列\(\left\{ {{b}_{n}} \right\}\)满足:\({{b}_{1}}={{a}_{1}},{{b}_{n+1}}({{a}_{n+1}}-{{a}_{n}})={{b}_{n}}.\)其中\(n\in {{N}^{*}}\).

              \((\)Ⅰ\()\)求数列\(\left\{ {{a}_{n}} \right\}\)和\(\left\{ {{b}_{n}} \right\}\)的通项公式;

              \((\)Ⅱ\()\)设\({{c}_{n}}=\dfrac{{{a}_{n}}}{{{b}_{n}}}\),求证:数列\(\left\{ {{c}_{n}} \right\}\)的前\(n\)项的和\({{T}_{n}} > \dfrac{5}{9}(n\in {{N}^{*}}).\)

            • 7.

              设数列\(\left\{ {{a}_{n}} \right\}\)的前\(n\)项和为\({{S}_{n}}\),已知\(\dfrac{{{S}_{n}}}{2}={{a}_{n}}-{{2}^{n}} (\)\(n\)\(∈N*)\).

              \((1)\)求\({{a}_{1}}\)的值,若\({{a}_{n}}={{2}^{n}}{{c}_{n}}\),证明数列\(\{{{c}_{n}}\}\)是等差数列;

              \((2)\)设\({{b}_{n}}={{\log }_{2}}{{a}_{n}}-{{\log }_{2}}(n+1)\),数列\(\{\dfrac{1}{{{b}_{n}}}\}\)的前\(n\)项和为\({{B}_{n}}\),若存在整数\(m\),使对任意\(n\)\(∈\)\(N\)\(*\)且\(n\)\(\geqslant 2\),都有\({{B}_{3n}}-{{B}_{n}} > \dfrac{m}{20}\)成立,求\(m\)的最大值.

            • 8.
              已知等差数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),\(S_{5}=35\),\(a_{5}\)和\(a_{7}\)的等差中项为\(13\).
              \((1)\)求\(a_{n}\)及\(S_{n}\);
              \((2)\)令\(b_{n}= \dfrac {1}{a_{n}^{2}-1}(n∈N^{*})\),求数列\(\{b_{n}\}\)的前项和\(T_{n}\).
            • 9.

              已知公差不为零的等差数列\(\left\{{a}_{n}\right\} \)中,\({{a}_{3}}=7\),且\({{a}_{1}},{{a}_{4}},{{a}_{13}}\)成等比数列

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

              \((2)\)令\({{b}_{n}}=\dfrac{1}{{{a}^{2}}_{n}-1}\) \((n∈N^{*})\),求数列\(\left\{{b}_{n}\right\} \)的前\(n\)项和\({{S}_{n}}\)

            • 10.

              已知数列\(\{b_{n}\}\)是首项为\(2\)且公比为\(q\)的等比数列,数列\(\{a_{n}\}\)满足\(a_{1}=3q\),\(a_{n+1}-qb_{n+1}=a_{n}-qb_{n}(n∈N^{*}).\)

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

              \((2)\)若\(q= \dfrac{1}{2} \),数列\(\{b_{n}\}\)前\(n\)项和为\(S_{n}\),求所有满足等式\( \dfrac{{S}_{n}-m}{{S}_{n+1}-m}= \dfrac{1}{{b}_{m}+1} \)成立的正整数\(m\),\(n\);

              \((3)\)若\(q < 0\),且对任意\(m\),\(n∈N^{*}\),都有\( \dfrac{{a}_{m}}{{a}_{n}}∈\left( \dfrac{1}{6},6\right) \),求实数\(q\)的取值范围.

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