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            • 1.

              若各项均为正数的数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),且\(2 \sqrt[]{S_{n}}=a_{n}+1 (n∈N*)\).

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

              \((2)\)若正项等比数列\(\{b_{n}\}\),满足\(b_{2}=2\),\(2b_{7}+b_{8}=b_{9}\),求\(T_{n}=a_{1}b_{1}+a_{2}b_{2}+…+a_{n}b_{n}\);

              \((3)\)对于\((2)\)中的\(T_{n}\),若对任意的\(n∈N^{*}\),不等式\(λ·(-1)^{n} < \dfrac{1}{2^{n+1}}(T_{n}+21)\)恒成立,求实数\(λ\)的取值范围.

            • 2.

              用分期付款的方式购买家用电器需\(11500\)元,购买当天先付\(1500\)元,以后每月交付\(500\)元,并加付利息,月利率为\(0.5\%\),若从交付\(1500\)元后的第\(1\)个月开始算分期付款的第\(1\)个月,问:

              \((1)\)分期付款的第\(10\)个月应交付多少钱?

              \((2)\)全部贷款付清后,买家用电器实际花了多少钱?

            • 3. 已知数列\(\{ \)\(a_{n}\)\(\}\)的前 \(n\)项和为 \(S_{n}\)\(a_{n}\)\(=\) \(n\)\(·2\) \({\,\!}^{n}\),则 \(S_{n}\)\(=\)________.
            • 4.

              已知数列\(\left\{{b}_{n}\right\} \)是等差数列,\({b}_{1}=1,{b}_{1}+{b}_{2}+…+{b}_{10}=145 \).

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

              \((2)\)设数列\(\left\{{a}_{n}\right\} \)的通项\({a}_{n}={\log }_{a}\left(1+ \dfrac{1}{{b}_{n}}\right) (\)其中\(a > 0\)且\(a\neq 1 )\)记\({S}_{n} \)是数列\(\left\{{a}_{n}\right\} \)的前\(n\)项和,试比较\({S}_{n} \)与\(\dfrac{1}{3}{\log }_{a}{b}_{n+1} \)的大小,并证明你的结论.

            • 5.

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

              \((\)Ⅰ\()\)求\(a_{2}{,}a_{3}\)的值;

              \((\)Ⅱ\()\)设\(b_{n}{=}2a_{n}{-}2n{-}1\),求数列\(\{ b_{n}\}\)的前\(n\)项和\(T_{n}\).

            • 6.

              在等差数列\(\left\{{a}_{n}\right\} \)中,\({a}_{1}=-2008 \),其前\(n\)项和为\(S_{n}\),若\(\dfrac{{S}_{12}}{12}- \dfrac{{S}_{10}}{10}=2 \),则\(S_{2008}\)的值等于______ .

            • 7.

              等差数列\({a_{n}}\)中,\(S_{n}\)是它的前\(n\)项之和,且\(S_{6} < S_{7}\),\(S_{7} > S_{8}\),则

              \(①\)比数列的公差\(d < 0\)         \(②S_{9}\)一定小于\(S_{6}\)

              \(③a_{7}\)是各项中最大的一项      \(④S_{7}\)一定是\(S_{n}\)中的最大值

              其中正确的是              \((\)填入你认为正确的所有序号\()\)

            • 8.
              已知等差数列\(\{ a_{n}\}\)中公差\(d{\neq }0\),有\(a_{1}{+}a_{4}{=}14\),且\(a_{1}\),\(a_{2}\),\(a_{7}\)成等比数列.
              \((1)\)求\(\{ a_{n}\}\)的通项公式\(a_{n}\)与前\(n\)项和公式\(S_{n}\);
              \((2)\)令\({b}_{n}= \dfrac{{S}_{n}}{n} \),求数列\(\{\dfrac{1}{b_{n}b_{n{+}1}}\}\)的前\(n\)项和\(T_{n}\).
            • 9. 若两个等差数列\(\{a_{n}\}\)、\(\{b_{n}\}\)的前\(n\)项和分别为\(A_{n}\)、\(B_{n}\),且满足\( \dfrac {A_{n}}{B_{n}}= \dfrac {4n+2}{5n-5}\),则\( \dfrac {a_{5}+a_{13}}{b_{5}+b_{13}}\)的值为\((\)  \()\)
              A.\( \dfrac {7}{9}\)
              B.\( \dfrac {8}{7}\)
              C.\( \dfrac {19}{20}\)
              D.\( \dfrac {7}{8}\)
            • 10. 数列\(\{ \)\(a_{n}\)\(\}\)的前 \(n\)项和为 \(S_{n}\)\(a\)\({\,\!}_{1}=1\), \(S_{n}\)\({\,\!}_{+1}=4\) \(a_{n}\)\(+2( \)\(n\)\(∈N^{*})\),设 \(b_{n}\)\(=\) \(a_{n}\)\({\,\!}_{+1}-2\) \(a_{n}\)

              \((1)\)求证:\(\{\)\(b_{n}\)\(\}\)是等比数列;

              \((2)\)设\(c_{n}\)\(= \dfrac{a_{n}}{3n-1}\),求证:\(\{\)\(c_{n}\)\(\}\)是等比数列.

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