2017年甘肅高考數(shù)學(xué)基礎(chǔ)提升訓(xùn)練(一)
1.等差數(shù)列{an}的通項(xiàng)公式為an=2n+1,其前n項(xiàng)和為Sn,則數(shù)列n的前10項(xiàng)和為( )
A.70 B.75
C.100 D.120
2.已知等比數(shù)列{an}的各項(xiàng)均為正數(shù),且a5a6+a4a7=18,則log3a1+log3a2+…+log3a10=( )
A.12 B.10
C. 8 D.2+log3 5
3.等差數(shù)列{an}的前n項(xiàng)和為Sn (n=1,2,3,…),若當(dāng)首項(xiàng)a1和公差d變化時(shí), a5+a8+a11是一個(gè)定值,則下列選項(xiàng)中為定值的是( )
A.S17 B.S16
C.S15 D.S14
4. 數(shù)列{an}的前n項(xiàng)和為Sn,若an=n(n+2),則S10等于( )
A..12 B.24
C.132 D.264
5.設(shè)等比數(shù)列{an}的各項(xiàng)均為正數(shù),其前n項(xiàng)和為Sn.若a1=1,a3=4,Sk=63,則k=________.
6.等差數(shù)列{an}的前n項(xiàng)和為Sn ,且滿足S35=S3992,a=(1,an),b=(2014,a2014),則a·b的值為( )
A.2014 B.-2014
C.1 D.0
7.已知一次函數(shù)f(x)=kx+b的圖像經(jīng)過點(diǎn)P(1,2)和Q(-2,-4),令an=f(n)f(n+1),n∈N*,記數(shù)列an的前n項(xiàng)和為Sn,當(dāng)Sn=25時(shí),n的值為( )
A.24 B.25
C.23 D.26
8.已知冪函數(shù)y=f(x)的圖像過點(diǎn)(4,2),令an=f(n+1)+f(n),n∈N*,記數(shù)列an的前n項(xiàng)和為Sn,則當(dāng)Sn=10時(shí),n的值是( )
A.110 B.120
C.130 D.140
9.數(shù)列滿足a1=2,a2=1,an-1-an=an-an+1(n≥2),則數(shù)列的第100項(xiàng)為( )
A.2100 B.250
C.100 D.50
10.設(shè)數(shù)列{an}滿足a1=2,an+1=4an-3n+1,n∈N*,則數(shù)列{an}的前n項(xiàng)和可以表示為( )
11.設(shè)直線nx+(n+1)y=(n∈N*)與兩坐標(biāo)軸圍成的三角形的面積為Sn,則S1+S2+…+S2014=________ .
12.在數(shù)列{an}中,a1=1,a2=2,且an+2-an=1+(-1)n(n∈N*),則S100=________ .
13.已知數(shù)列{an}中,a1=1,a2n=n-an,a2n+1=an+1,則a1+a2+a3+…+a100=________.
14.已知數(shù)列{an}與{bn},若a1=3且對(duì)任意正整數(shù)n滿足an+1-an=2, 數(shù)列{bn}的前n項(xiàng)和Sn=n2+an.
(1)求數(shù)列{an},{bn}的通項(xiàng)公式;
(2)求數(shù)列bnbn+1的前n項(xiàng)和Tn.
15.已知函數(shù)f(x)=4x,數(shù)列{an}中,2an+1-2an+an+1an=0,a1=1,且an≠0, 數(shù)列{bn}中, b1=2,bn=fan-1(n≥2,n∈N*).
(1)求證:數(shù)列an是等差數(shù)列,并求數(shù)列{an}的通項(xiàng)公式;
(2)求數(shù)列an的前n項(xiàng)和Tn.
16.在數(shù)列{an}中,a1=1,an+1=an+3(n∈N*).
(1)試說明2是等比數(shù)列,并求數(shù)列{an}的通項(xiàng)公式;
(2)數(shù)列{bn}滿足bn=(3n-1)·2n·an,數(shù)列{bn}的前n項(xiàng)和為Tn,若不等式(-1)nλ<Tn+2n-1對(duì)一切n∈N*恒成立,求λ的取值范圍.