1、北京师大附中20072008学年度高三第一轮复习高三数学(文)统练5(考试时间:2007.10.9)第卷(试题)一、选择题:本大题共10小题,每小题6分,共60分在每小题给出的四个选项中,只有一项是符合题目要求的1已知等差数列an满足:a1 + a2 + a3 + + a101 = 0,则有( C )Aa1 + a1010 Ba2 + a1000 Ca3 + a99 = 0 Da51 = 512若Sn是数列an的前n项和,且Sn = n2 + 1,则an是( D )A等比数列,但不是等差数列 B等差数列,但不是等比数列C等差数列,而且也是等比数列 D既非等差数列也非等比数列3若数列an的前n项
2、和Sn = 3na,若数列an为等比数列,则实数a的取值是( B )A3 B1 C0 D14设Sn是等差数列an的前n项和,若=,=( A )A1 B1 C2 D5设f (n ) = 2 + 24 + 27 + 210 + + 23n + 10(nN),则f (n )等于( D )A(8n1) B(8n + 11) C(8n + 31) D(8n+ 41)6函数y = x3 + ax + b在区间(1,1)上为减函数,在(1,+)上为增函数,则( D )Aa = 1,b = 1 Ba = 1,bR Ca =3,b = 3 Da =3,bR7函数f (x ) = x22ax + 5在区间1,2上
3、存在反函数的一个充分不必要条件是( A )Aa(,0 Ba1,2 Ca(,02,+) Da0,+)8函数y = | x21| + 1的图象与函数y = 2x的图象交点的个数为( C )A1 B2 C3 D49函数y = 2x + 1(x0)的反函数是( A )Ay =,x(1,2) By =,x(1,2)Cy =,x(1,2 Dy =,x(1,2ABCD10已知函数y =(x )的图象如下图所示(其中(x )是函数f (x )的导函数),下面四个图象中y = f (x )的图象大致是( C )二填空题:本大题共6小题,每小题7分,共42分把答案填在题中横线上11若函数f (x ) =的定义域为
4、R,则实数a的取值范围是 .答案:1,012已知等差数列an的公差不为0,且a1,a3,a9成等比数列,则= .13等差数列an中,首项a10,Sn是前n项和,且S15 = S25,则Sn最大时,n = .2014在数列an中,a1 = 1,a2 = 2,且an +2an = 1 + (1)n(nN*),则S100 = .260015数列an中,an = (3n + 2)()n(nN*),则an中最大的项是第 项.916等差数列an、bn的前n项和Sn、Tn满足,则= .答案:=.北京师大附中20072008学年度高三第一轮复习高三数学(文)统练5第II卷(答题卡)一、选择题(共10小题,每小
5、题4分,共40分)在每小题给出的四个选项中,只有一项是符合题目要求的.题 号12345678910答 案二、填空题(共6小题,每小题4分,共24分)11 ;12 ;13 ;14 ;15 ;16 ;三、解答题(共3小题,每小题12分,共36分)解答应写出文字说明,证明过程,或演算步骤)17数列an的前n项和为Sn,且a1 = 1,an +1 =Sn,n = 1,2,3,求:(1)a2,a3,a4的值及数列an的通项公式;(2)a2 + a4 + a6 + + a2n的值.解:(1) a1 = 1,an +1 =Sn, a2 =S1 =a1 =;a3 =S2 =(1 +) =;a4 =S3 =(a
6、1 + a2 + a3) =) =.(2)由an +1 =Sn,及n2时,得an =Sn1, an +1an =(SnSn1) =an1,即an +1 =an,故数列an是除去a1 = 1后是等比数列,公比q =; an =.数列a2n是等比数列,且首项a2 =,公比为, a2 + a4 + a6 + + a2n =.18已知对于x的所有实数值,二次函数f (x ) = x24ax + 2a + 12(aR)的值都是非负的,求关于x的方程= | a1| + 2的根的取值范围.解:依题,得= 16a24 (2a + 12)0,解得a2. 由= | a1| + 2,得x = (a + 2)(| a
7、1| + 2),当a1时,x = (a + 2) (3a) =(a)2 +. x;当1a2时,x = (a + 2) (a + 1), 6a12;综上可知,方程根的取值范围是,12.19已知函数f (x )对任意的xR都有f (x ) + f (1x) =.(1)求f ()和f () + f ()(nN*)的值;(2)数列an满足an = f (0) + f () + f () + + f () + f (1),求数列an的通项公式an;(3)令bn = (an)3n,数列bn的前n项的和Sn.解:(1) 函数f (x )对任意的xR都有f (x ) + f (1x) =. 令x =时,f (
8、) + f () =,解得f () =; 令x =时,则f () + f () =.(2)由(1)可知, f () + f () =,故有:f (0) + f (1) = f () + f () = =,an = f (0) + f () + f () + + f () + f () + f (1),an = f (1) + f () + f () + + f () + f () + f (0),上面二式相加,得:2an = n f (0) + f (1) =(n + 1),解得an =.(3)由(2)可知,bn = (an)3n =n3n, Sn =3 +232 +333 +434 + +n3n, 3 Sn =32 +233 +334 + +(n1)3n +n3n + 1, ,得: 2Sn =(3 + 32 + 33 + + 3n )n3n + 1 =n3n + 1 =(12n)3n +1.故Sn =(2n1)3n +1 +.