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            • 1.

              已知数列\(\left\{{a}_{n}\right\} \)满足\({a}_{1}=1 \),\({a}_{n+1}-{a}_{n}\geqslant 2\left(n∈{N}^{*}\right) \),则\((\)     \()\)


              A.\({a}_{n}\geqslant 2n+1 \)
              B.\({a}_{n}\geqslant {2}^{n-1} \)
              C.\({S}_{n}\geqslant {n}^{2} \)
              D.\({S}_{n}\geqslant {2}^{n-1} \)
            • 2.
              在等差数列\(\{a_{n}\}\)中,首项\(a_{1}=0\),公差\(d\neq 0\),若\(a_{m}=a_{1}+a_{2}+…+a_{9}\),则\(m\)的值为\((\)  \()\)
              A.\(37\)
              B.\(36\)
              C.\(20\)
              D.\(19\)
            • 3. 等差数列\(\{a_{n}\}\)中,\(a_{10} < 0\),\(a_{11} > 0\),且\(a_{11} > |a_{10}|\),\(S_{n}\)为数列\(\{a_{n}\}\)的前\(n\)项和,则使\(S_{n} > 0\)的\(n\)的最小值为\((\)  \()\)
              A.\(21\)
              B.\(20\)
              C.\(10\)
              D.\(11\)
            • 4.

              等差数列\(\left\{ {{a}_{n}} \right\}\)中,\({{a}_{3}}=4\),前\(11\)项的和\(S_{11}=110\)则\(a_{9}=\)

              A.\(10\)
              B.\(12\)
              C.\(14\)
              D.\(16\)
            • 5.

              设\(S_{n}\)是等差数列\(\{a_{n}\}\)的前\(n\)项和,若\( \dfrac{a_{7}}{a_{5}}= \dfrac{9}{13}\),则\( \dfrac{S_{13}}{S_{9}}= (\)  \()\)

              A.\(1\)                         
              B.\(-1\)                                 
              C.\(2\)                                  
              D.\( \dfrac{1}{2}\)
            • 6.

              设等差数列\(\left\{ a_{n} \right\}\)的前\(n\)项和为\(S_{n}\),若\(a_{1}{=-}11\),\(a_{4}{+}a_{6}{=-}6\),则当\(S_{n}\)取最小值时,\(n\)等于(    )

              A.\(9\)   
              B.\(8\)   
              C.\(7\)   
              D.\(6\)
            • 7.

              等差数列的前\(n\)项和公式是常数项为\(0\)的二次函数\(.\)(    )

              A.\(√\)   
              B.\(×\)
            • 8.
              在等差数列\(\{a_{n}\}\)中,首项\(a_{1}=0\),公差\(d\neq 0\),若\(a_{k}=a_{1}+a_{2}+a_{3}+…+a_{10}\),则\(k=(\)  \()\)
              A.\(45\)
              B.\(46\)
              C.\(47\)
              D.\(48\)
            • 9.
              设\(S_{n}\)为等差数列\(\{a_{n}\}\)的前\(n\)项和,若\(a_{1}=1\),公差\(d=2\),\(S_{k+2}-S_{k}=24\),则\(k=(\)  \()\)
              A.\(8\)
              B.\(7\)
              C.\(6\)
              D.\(5\)
            • 10.

              已知等差数列\(\{a_{n}\}\)中,公差\(d=2\),\(a_{n}=11\),\(S_{n}=35\),则\(a_{1}=(\)    \()\)

              A.\(5\)或\(7\)
              B.\(3\)或\(5\)
              C.\(7\)或\(-1\)
              D.\(3\)或\(-1\)
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