設
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是公差不為0的等差數(shù)列
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的前
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項和,若
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,則
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( )
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科目:高中數(shù)學
來源:不詳
題型:解答題
已知數(shù)列
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滿足:

數(shù)列
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滿足
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。
(1)若
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是等差數(shù)列,且
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求
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的值及
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的通項公式;
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科目:高中數(shù)學
來源:不詳
題型:解答題
設數(shù)列
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,
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,若以
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為系數(shù)的二次方程:
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都有根
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滿足
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.
(1)求證:
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為等比數(shù)列
(2)求

.
(3)求
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的前

項和

.
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科目:高中數(shù)學
來源:不詳
題型:解答題
已知數(shù)列

的首項
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其中
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,
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令集合

.
(Ⅰ)若
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,寫出集合

中的所有的元素;
(Ⅱ)若
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,且數(shù)列
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中恰好存在連續(xù)的7項構成等比數(shù)列,求
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的所有可能取值構成的集合;
(Ⅲ)求證:
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.
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科目:高中數(shù)學
來源:不詳
題型:填空題
數(shù)列

的前

項和是

,若數(shù)列

的各項按如下規(guī)則排列:

,
若存在正整數(shù)
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,使
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,
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,則
.
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科目:高中數(shù)學
來源:不詳
題型:填空題
已知等差數(shù)列

的前
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項和是
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,則使
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的最小正整數(shù)
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等于
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科目:高中數(shù)學
來源:不詳
題型:單選題
已知等差數(shù)列

中,
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,記數(shù)列

的前
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項和為
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,若
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,對任意的
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成立,則整數(shù)
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的最小值為( )
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科目:高中數(shù)學
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已知各項為正數(shù)的等差數(shù)列

的前
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項和為
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,那么

的最大值為( )
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