某小朋友用手指按如圖所示的規(guī)則練習(xí)數(shù)數(shù),數(shù)到2009時對應(yīng)的指頭是
。(填出指頭名稱:各指頭對應(yīng)依次為大拇指、食指、中指、無名指、小拇指)
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從第二行起,周期為8得對應(yīng)的指頭是大拇指.
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相關(guān)習(xí)題
科目:高中數(shù)學(xué)
來源:不詳
題型:解答題
若一個數(shù)列各項取倒數(shù)后按原來的順序構(gòu)成等差數(shù)列,則稱這個數(shù)列為調(diào)和數(shù)列.已知數(shù)列

是調(diào)和數(shù)列,對于各項都是正數(shù)的數(shù)列
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,滿足
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.
(Ⅰ)證明數(shù)列
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是等比數(shù)列;
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(Ⅱ)把數(shù)列
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中所有項按如圖所示的規(guī)律排成一個三角形
數(shù)表,當(dāng)
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時,求第
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行各數(shù)的和;
(Ⅲ)對于(Ⅱ)中的數(shù)列
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,證明:
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.
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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14分)
在數(shù)列
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與
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中,
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,數(shù)列
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的前
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項和
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滿足
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,
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為
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與

的等比中項,
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.
(Ⅰ)求
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的值;
(Ⅱ)求數(shù)列

與

的通項公式;
(Ⅲ)設(shè)
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.證明
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.
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科目:高中數(shù)學(xué)
來源:不詳
題型:解答題
數(shù)列

的各項均為正數(shù),
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為其前
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項和,對于任意
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,總有
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成等差數(shù)列.
(1)求數(shù)列
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的通項公式;
(2)若b
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=a
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4
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(
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), B
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是數(shù)列{b
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}的前
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項和, 求證:不等式 B
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≤4B
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,對任意
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皆成立.
(3)令
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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)
(注意:在試題卷上作答無效)
設(shè)函數(shù)
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.?dāng)?shù)列
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滿足
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,

.
(Ⅰ)證明:函數(shù)
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在區(qū)間
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是增函數(shù);
(Ⅱ)證明:

;
(Ⅲ)設(shè)
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,整數(shù)
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.證明:
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.
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科目:高中數(shù)學(xué)
來源:不詳
題型:解答題
某商店投入38萬元經(jīng)銷某種紀(jì)念品,經(jīng)銷時間共60天,為了獲得更多的利潤,商店將每天獲得的利潤投入到次日的經(jīng)營中,市場調(diào)研表明,該商店在經(jīng)銷這一產(chǎn)品期間第

天的利潤
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(單位:萬元,
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),記第
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天的利潤率
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,例如
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小題1:求

的值;
小題2:求第
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天的利潤率

;
小題3:該商店在經(jīng)銷此紀(jì)品期間,哪一天的利潤率最大?并求該天的利潤率。
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科目:高中數(shù)學(xué)
來源:不詳
題型:解答題
設(shè)等差數(shù)列

的前
n項和為
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;設(shè)
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,問
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是否可能為一與
n無關(guān)的常數(shù)?若不存在,說明理由.若存在,求出所有這樣的數(shù)列的通項公式.
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科目:高中數(shù)學(xué)
來源:不詳
題型:單選題
已知公差不為0的等差數(shù)列
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滿足
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成等比數(shù)列,
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項和,則
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的值為 ( )
A.2 | B.3 | C. | D.不存在 |
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