基礎(chǔ)鞏固組
1.數(shù)列0,,…的一個(gè)通項(xiàng)公式為( )
A.an=(nN*) B.an=(n∈N*)
C.an=(n∈N*) D.an=(n∈N*)
2.若Sn為數(shù)列{an}的前n項(xiàng)和,且Sn=,則等于( )
A. B. C. D.30
3.(2014寧夏銀川模擬改編)設(shè)數(shù)列{an}滿(mǎn)足:a1=2,an+1=1-,記數(shù)列{an}的前n項(xiàng)之積為T(mén)n,則T2 015的值為( )
A.- B.-1 C. D.2
4.已知數(shù)列{an}的前n項(xiàng)和為Sn,a1=1,Sn=2an+1,則Sn等于( )
A.2n-1 B. C. D.
5.數(shù)列{an}滿(mǎn)足:a1+3a2+5a3+…+(2n-1)·an=(n-1)·3n+1+3(nN*),則數(shù)列{an}的通項(xiàng)公式an= .
6.已知數(shù)列{an}的通項(xiàng)公式為an=(n+2),則當(dāng)an取得最大值時(shí),n= .
7.設(shè){an}是首項(xiàng)為1的正項(xiàng)數(shù)列,且(n+1)-n+an+1·an=0(n=1,2,3,…),則它的通項(xiàng)公式an= .
8.設(shè)數(shù)列{an}的前n項(xiàng)和為Sn.已知a1=1,=an+1-n2-n-,nN*.
(1)求a2的值;
(2)求數(shù)列{an}的通項(xiàng)公式.
9.已知函數(shù)f(x)=ax2+bx(a≠0)的導(dǎo)函數(shù)f'(x)=-2x+7,數(shù)列{an}的前n項(xiàng)和為Sn,點(diǎn)Pn(n,Sn)(nN*)均在函數(shù)y=f(x)的圖象上,求數(shù)列{an}的通項(xiàng)公式及Sn的最大值.
能力提升組
10.(2014湖南長(zhǎng)沙模擬)已知函數(shù)f(x)是定義在(0,+∞)上的單調(diào)函數(shù),且對(duì)任意的正數(shù)x,y都有f(xy)=f(x)+f(y).若數(shù)列{an}的前n項(xiàng)和為Sn,且滿(mǎn)足f(Sn+2)-f(an)=f(3)(nN*),則an等于( )
A.2n-1 B.n C.2n-1 D.
11.已知數(shù)列{an}滿(mǎn)足:a1=1,an+1=(nN*).若bn+1=(n-λ),b1=-λ,且數(shù)列{bn}是單調(diào)遞增數(shù)列,則實(shí)數(shù)λ的取值范圍為( )
A.λ>2 B.λ>3 C.λ<2 D.λ<3
12.(2014福建龍巖模擬)數(shù)列{an}滿(mǎn)足an+1=a1=,則數(shù)列的第2 015項(xiàng)為 .
13.(2014安徽合肥質(zhì)檢)已知數(shù)列{an}滿(mǎn)足:a1=1,2n-1an=an-1(nN,n≥2).
(1)求數(shù)列{an}的通項(xiàng)公式;
(2)這個(gè)數(shù)列從第幾項(xiàng)開(kāi)始及其以后各項(xiàng)均小于?
14.設(shè)數(shù)列{an}的前n項(xiàng)和為Sn,數(shù)列{Sn}的前n項(xiàng)和為T(mén)n,滿(mǎn)足Tn=2Sn-n2,nN*.
(1)求a1的值;
(2)求數(shù)列{an}的通項(xiàng)公式.