已知等
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差數(shù)列{
an}的公差
d≠0,它的第1、5、17項(xiàng)順次成等比數(shù)列,
則這個等比數(shù)列的公比是
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科目:高中數(shù)學(xué)
來源:不詳
題型:解答題
已知數(shù)列
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和

中,數(shù)列

的前

項(xiàng)和記為

. 若點(diǎn)
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在函數(shù)

的圖象上,點(diǎn)

在函數(shù)

的圖象上。
(Ⅰ)求數(shù)列

的通項(xiàng)公式;
(Ⅱ)求數(shù)列

的前

項(xiàng)和

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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13分)
已知數(shù)列{ a
n }的前n項(xiàng)和S
n滿足,S
n=2a
n+(—1)
n,n≥1。
(1)求數(shù)列{ a
n }的通項(xiàng)公式;
(2)求證:對任意整數(shù)m>4,有

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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)已知數(shù)列

滿足

為

的前n項(xiàng)和。
(1)求證:數(shù)列

是等比數(shù)列,并求

的通項(xiàng)公式;
(2)如果對于任意

,不等式

恒成立,求實(shí)數(shù)

的取值范圍.
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科目:高中數(shù)學(xué)
來源:不詳
題型:解答題
已知等差數(shù)列

的前

項(xiàng)和為

,

(1)求數(shù)列

的通項(xiàng)公式

與前

項(xiàng)和

;
(2)設(shè)

求證:數(shù)列

中任意不同的三項(xiàng)都不可能成為等比數(shù)列.
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科目:高中數(shù)學(xué)
來源:不詳
題型:解答題
f(x)=

x
2+

x,數(shù)列{a
n}的前n項(xiàng)和為S
n,點(diǎn)(n,S
n)(n∈N
*)均在函數(shù)y=f(x)的圖象上.
(Ⅰ)求數(shù)列{a
n}的通項(xiàng)公式a
n;
(Ⅱ)令b
n=

,求數(shù)列{b
n}的前n項(xiàng)和T
n
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科目:高中數(shù)學(xué)
來源:不詳
題型:解答題
已知各項(xiàng)為正數(shù)的數(shù)列

的前

項(xiàng)和為

,且滿足

,
(1)求數(shù)列

的通項(xiàng)公式
(2)令

,數(shù)列

的前

項(xiàng)和為

,若
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對一切
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恒成立,求

的最小值.
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科目:高中數(shù)學(xué)
來源:不詳
題型:單選題
在等比數(shù)列

中,

>0,且


+2


+
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
=25,那么

+
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=( )
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