當(dāng)且僅當(dāng)n=1時.有最小值1.∴λ<1. --10分 查看更多

 

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(2013•浙江模擬)已知數(shù)列{an}的前n項(xiàng)和為Sn,且a1=
1
4
,an+1=Sn+
t
16
(n∈N*,t為常數(shù)).
(Ⅰ)若數(shù)列{an}為等比數(shù)列,求t的值;
(Ⅱ)若t>-4,bn=lgan+1,數(shù)列{bn}前n項(xiàng)和為Tn,當(dāng)且僅當(dāng)n=6時Tn取最小值,求實(shí)數(shù)t的取值范圍.

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已知數(shù)列{an}的前n項(xiàng)和為Sn,且a1=
1
4
,an+1=Sn+
t
16
(n∈N*,t為常數(shù)).
(Ⅰ)若數(shù)列{an}為等比數(shù)列,求t的值;
(Ⅱ)若t>-4,bn=lgan+1,數(shù)列{bn}前n項(xiàng)和為Tn,當(dāng)且僅當(dāng)n=6時Tn取最小值,求實(shí)數(shù)t的取值范圍.

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已知數(shù)列{an}的前n項(xiàng)和為Sn,且a1=,an+1=Sn+(n∈N*,t為常數(shù)).
(Ⅰ)若數(shù)列{an}為等比數(shù)列,求t的值;
(Ⅱ)若t>-4,bn=lgan+1,數(shù)列{bn}前n項(xiàng)和為Tn,當(dāng)且僅當(dāng)n=6時Tn取最小值,求實(shí)數(shù)t的取值范圍.

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已知向量p//q,其中R且>0,,把其中,所滿足的關(guān)系式記為,若函數(shù)為奇函數(shù),且當(dāng)>0時,有最小值

(1)求函數(shù)的表達(dá)式;

(2)設(shè)數(shù)列滿足如下關(guān)系:N*),且

,求數(shù)列的通項(xiàng)公式,并求數(shù)列N*)前項(xiàng)的和S

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(理)已知函數(shù)f(x)=(0<x<1)的反函數(shù)為f-1(x),設(shè)它在點(diǎn)(n,f-1(n))(n∈N*)處

的切線在Y軸上的截距為bn,數(shù)列{an}滿足:a1=2,an+1=f-1(an)(n∈N*).

(1)求數(shù)列{an}的通項(xiàng)公式;

(2)在數(shù)列{}中,僅當(dāng)n=5時,取最小值,求A的取值范圍;

(3)令函數(shù)g(x)=f-1(x)(1+x)2,數(shù)列{cn}滿足:c1=,cn+1=g(cn)(n∈N*),求證:對于一切

n≥2的正整數(shù),都滿足:1<<2.

(文)已知函數(shù)f(x):(0<x<1)的反函數(shù)為f-1(x),數(shù)列{an}滿足:a1=2,an+1=f-1(an) (n∈N*).

(1)求數(shù)列{an}的通項(xiàng)公式;

(2)設(shè)函數(shù)g(x)=f-1(x)(1+x)2在點(diǎn)(n,g(n))(n∈N*)處的切線在Y軸上的截距為bn,求數(shù)列{bn}的通項(xiàng)公式;

(3)在數(shù)列{bn+}中,僅當(dāng)n=5時,bn+取最大值,求λ的取值范圍.

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