在等比數(shù)列
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中,
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,則
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的值( )
A. 3 B9 C.
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D.
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科目:高中數(shù)學(xué)
來源:不詳
題型:解答題
(本小題滿分12分)等比數(shù)列{
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}的前n 項和為
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,已知
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成等差數(shù)列
(1)求
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的公比
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;
(2)若
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,求
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科目:高中數(shù)學(xué)
來源:不詳
題型:單選題
設(shè)等比數(shù)列
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的公比
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前
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項和為
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若
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則
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( )
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科目:高中數(shù)學(xué)
來源:不詳
題型:填空題
用符號
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表示超過
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的最小整數(shù),如
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,
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。有下列命題:①若函數(shù)
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,
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,則值域為
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;②若
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,則方程
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有三個根;③若
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、
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,則
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的概率
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;④如果數(shù)列
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是等比數(shù)列,
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,那么數(shù)列
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一定不是等比數(shù)列。其中正確的是
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科目:高中數(shù)學(xué)
來源:不詳
題型:填空題
各項均為正數(shù)的等比數(shù)列
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中,若
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,則
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________。
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科目:高中數(shù)學(xué)
來源:不詳
題型:填空題
設(shè)各項都不同的等比數(shù)列{
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}的首項為
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,公比為
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,前
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項和為
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,要使數(shù)列{
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}為等比數(shù)列,則必有
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=________.
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