2017-2018学年高二下学期期中考试数学(文)试题
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一、选择题:(本大题共12小题,每小题5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,把答案填写在答题卷相应位置上)1.已知集合{|320}A x x =-<, 2{|2}B x x x =≤,则A B ⋂=( ) A .3[0,)2 B .3[0,]2 C .3(,2)2 D .3(,2]22.25πsin 6等于( )A .12 BC .12- D.3.设f (x )=⎩⎪⎨⎪⎧2e x -1,x <2,log 3(2x-1),x ≥2,则f [f (2)]等于( ) A .0 B .1 C .2D .34.下列函数中,随x 增大而增大速度最快的是( )A .y =2 006ln xB .y =x 2 006C .y =e x2 006D .y =2 006·2x5.下列函数中,最小正周期为π的奇函数是( )(A )y =sin (2x +2π) (B)y =cos (2x +2π) (C )y =sin 2x +cos 2x (D ) y =sinx +cosx 6.函数=ln1|2x -3|的大致图象为(如图所示)( ).7.已知2sin cos 2cos 3sin =-+αααα,则2cos sin cos ααα+⋅=( )A.65 B.35 C.25 D.35-8. 设m R ∈,命题“若0m >,则方程20x x m +-=有实根”的逆否命题是( ) (A )若方程20x x m +-=有实根,则0m >(B) 若方程20x x m +-=有实根,则0m ≤ (C) 若方程20x x m +-=没有实根,则0m > (D) 若方程20x x m +-=没有实根,则0m ≤9. 下列说法正确的是( )A .“p 或q 为真命题”是“p 且q 为真命题”的充分不必要条件B .,“”是“1>a ”的必要不充分条件C .命题“R x ∈∃,使得0322<++x x ”的否定是:“R x ∈∀,0322>++x x ”D .命题p :“R x ∈∀,2cos sin ≤+x x ”,则p ⌝是真命题10. 0.22a =,20.2b =,0.2log 2c =的大小关系是( )A .c a b <<B .a b c <<C .b c a <<D .c a b << 11. 函数f (x )=1+x -sin x 在(0,2π)上是( )A .增函数B .减函数C .在(0,π)上增,在(π, 2π)上减D .在(0,π)上减,在(π,2π)上增 12.已知 ,(0,),sin sin 02παββααβ∈-> ,则下列不等式一定成立的是( )A.2παβ+< B.2παβ+=C.αβ<D.αβ> .二、填空题:(本大题共4小题,每小题5分,共20分.把答案填在答题卷的相应位置)13.已知函数f (x )=6x-log 2x ,在下列区间中,包含f (x )的有 零点。
14. 函数ln(1)y x =+的定义域15.如图,函数F (x )=f (x )+15x 2的图象在点P 处的切线方程是y =-x +8,则f (5)+f ′(5)=______.16.已知f 1(x )=sin x +cos x ,记f 2(x )=f 1′(x ),f 3(x )=f 2′(x ),…,f n (x )=f n -1′(x )(n ∈N *,n ≥2),则f 1(π2)+f 2(π2)+…+f 2 012(π2)=________.三、 解答题:(本大题共5小题,共70分.解答应写出文字说明、演算步骤或推证过程)17.(本小题满分10分)已知命题p :“∀x ∈[1,2],x 2-a ≥0”,命题q :“∃x 0∈R ,x 20+2ax 0+2-a =0”,若命题“p 且q ”是真命题,求实数a 的取值范围.18. (本小题满分12分)已知集合{}2280A x x x =--≤,{}23(m 1)(2m 1)0,B x x mx m R =-+-+≤∈. (Ⅰ)求集合A ; (Ⅱ) 若[1,4]A B =,求m 的值.19. (本小题满分12分)已知函数1()sin (sin ),[,]2444x x xf x x ππ=-∈-. (Ⅰ)求函数()f x 的单调区间; (Ⅱ)求函()f x 数的值域.20. (本小题满分12分) 已知函数ln ()xf x x a=+(a ∈R ),曲线()y f x =在点(1,(1))f 处的切线方程为1y x =-. (I )求实数a 的值。
(2)求()f x 的单调区间;21. (本小题满分12分)已知函数f (x )=A sin(ωx +φ)(x ∈R ,A >0,ω>0,|φ|<π2)的部分图象如图所示.(1)试确定f (x )的解析式;(2)若f (a 2π)=12,求cos(2π3-a )的值.22.(本小题满分12分)若函数f (x )=ax 3-bx +4,当x =2时,函数f (x )有极值-43.(1)求函数的解析式;(2)若关于x 的方程f (x )=k 有三个零点,求实数k 的取值范围.17-18下高二期中考试 数学文科答案卷1 D2 A3 C4 C5 B6 A7 A8 D9 B 10 B 11 A 12C13. 1 14. (-1,0) (0,3) 15. -5 16. 017.解:由“p 且q ”是真命题,则p 为真命题,q 也为真命题. 若p 为真命题,a ≤x 2恒成立, ∵x ∈[1,2],∴a ≤1.若q 为真命题,即x 2+2ax +2-a =0有实根, Δ=4a 2-4(2-a )≥0,即a ≥1或a ≤-2,综上,实数a 的取值范围为a ≤-2或a =1.18.解:(Ⅰ){}2280A x x x =--≤{}2x x x =-≤≤,(Ⅱ)由[1,4]A B =可得1x =为方程23(1)(21)0x mx m m -+-+=的根, 则13(1)(21)0m m m -+-+=,解之得0m =或2m =.当0m =,得{}{}21011B x x x x =-≤=-≤≤,此时[1,4]AB =,故0m ≠.当2m =,得{}{}265015B x xx x x =-+≤=≤≤,此时[1,4]A B =,故2m =. 19. 解:(Ⅰ)1()sin (sin )2444x x x f x =-21sin cos 2444x x x =-1cos 222x x =cos()23x π=+, 由2()223x k k ππππ-+≤+≤得824433k x k ππππ-+≤≤-+,令0k =得8233x ππ-≤≤-,令1k =得41033x ππ≤≤,由于83ππ-<-,43ππ>,从而可得()f x 的单调递增区间为2[,]3ππ--,单调递减区间为2(,]3ππ-.(Ⅱ)由于()f x cos()23x π=+,[,]ππ-,则5()6236x πππ-≤+≤,则cos()123x π≤+≤, 故函数()f x的值域为[. 20.解: 解:(I )依题意,2ln '()()x ax x f x x a +-=+, ·························································································· 2分 所以211'(1)(1)1a f a a+==++,又由切线方程可得'(1)1f =,即111a =+,解得0a =,......6分此时ln ()x f x x =,21ln '()xf x x-=, ············································································································· 9分 令'()0f x >,所以1ln 0x ->,解得0x e <<;令'()0f x <,所以1ln 0x -<,解得x e >,所以()f x 的增区间为:(0,)e ,减区间为:(,)e +∞. ·················································································· 12分21.解:(1)由题图可知A =2,T 4=56-13=12,∴T =2,ω=2πT =π.将点P (13,2),代入y =2sin(ωx +φ),得sin(π3+φ)=1.又|φ|<π2,∴φ=π6.故所求解析式为f (x )=2sin(πx +π6)(x ∈R).(2)∵f (a 2π)=12,∴2sin(a 2+π6)=12,即sin(a 2+π6)=14.∴cos(2π3-a )=cos[π-2(π6+a 2)]=-cos2(π6+a 2)=2sin 2(π6+a 2)-1=-78.22.解:由题意可知f ′(x )=3ax 2-b ,(1)于是⎩⎪⎨⎪⎧f ′(2)=12a -b =0,f (2)=8a -2b +4=-43,解得a=13 b=4 故所求的解析式为f (x )=13x 3-4x +4.(2)由(1)可知f ′(x )=x 2-4=(x -2)(x +2), 令f ′(x )=0,得x =2,或x =-2.因此,当x =-2时,f (x )有极大值283;当x =2时,f (x )有极小值-43.。