2017届高三强化班提优练习六
- 格式:docx
- 大小:27.06 KB
- 文档页数:2
1练习题(一)01.(2017年全国新课标1卷24)周灭商之后,推行分封制,如封武王弟康叔于卫,都朝歌(今河南淇县);封周公长子伯禽于鲁,都奄(今山东曲阜);封召公爽于燕,都蓟(今北京)。
分封( )A.推动了文化的交流与文化认同B.强化了君主专制权力C.实现了王室对地方的直接控制D.确立了贵族世袭特权 02.(2017年江苏卷单科历史1)《国语》讲“祀,国之大节”。
有学者认为,青铜器在商周时期被视为“政治的权力”。
可推断,商周时期青铜器主要作用( ) A.农具 B.礼器 C.食具 D.货币03.(2017年海南卷单科历史1)考古工作者在河南辉县琉璃阁发掘了一座春秋时期的诸侯墓,出土了只有周天子才能使用的九鼎。
这反映了( )A .宗法制度的瓦解 B .分封制度的崩溃C .等级制度的颠覆 D .礼乐制度的破坏04.(广西桂林市桂林中学2017届高三5月全程模拟考试文科综合--历史试题)下表是秦始皇时期所任丞相的情况,此表反映了秦朝05. (河南省南阳市第一中学2016-2017学年高二下学期第三次月考历史试题)秦朝中央政府中的九卿,其中的“奉常,掌宗庙礼仪”“郎中令,掌宫殿掖门戶”“卫尉,掌宫门卫屯兵”“宗正,掌彔属”“太仆,掌典马”“将作少府,掌治宫室”而隋唐中央政府吏、户、礼、兵,刑、工六部分掌官员考核任免,财政、札仅祭祀教育科举等、军政、司法和工程建设。
材料表明( )A. 中国古代家国—体政治特色消失B. 皇权旁落,相权加强C. 皇家事务与国家事务的逐步分离D. 机构精简,职能专一 06.(黑龙江省大庆实验中学2017届高三考前得分训练(六)文综历史试题)在秦代,官僚这种政治角色是从分封制下君主的家臣演变而来的,同时设置官府中掌管薄书案牍的吏胥,辅助官员履行政务。
这表明秦代( )A. 已出现了完整的官僚体系B. 平民政治已取代贵族政治C. 官僚政治的模式己经形成D. 中央文官的地位较为突出 07.(2017年北京卷13)北宋名臣包拯清正廉洁。
2017届高三强化班提优练习五1.点P 从(1,0)出发,沿单位圆x 2+y 2=1逆时针方向运动2π3弧长到达Q 点,则Q 点的坐标为________.2.已知角α的顶点与原点重合,始边与x 轴的正半轴重合,终边上一点P (-4,3),则cos (π2+α)sin (-π-α)cos (11π2-α)sin (9π2+α)的值为________.思维启迪 (1)准确把握三角函数的定义.(2)利用三角函数定义和诱导公式. 答案 (1)(-12,32) (2)-34解析 (1)设Q 点的坐标为(x ,y ), 则x =cos 2π3=-12,y =sin 2π3=32.所以Q 点的坐标为(-12,32).(2)原式=-sin α·sin α-sin α·cos α=tan α.根据三角函数的定义, 得tan α=y x =-34,所以原式=-34.3.如图,以Ox 为始边作角α(0<α<π),终边与单位圆相交于点P ,已知点P 的坐标为⎝⎛⎭⎫-35,45,则sin 2α+cos 2α+11+tan α=________.4.已知点P ⎝⎛⎭⎫sin 3π4,cos 3π4落在角θ的终边上,且θ∈[0,2π),则θ的值为________. 答案 (1)1825 (2)7π4解析 (1)由三角函数定义,得cos α=-35,sin α=45,∴原式=2sin αcos α+2cos 2α1+sin αcos α=2cos α(sin α+cos α)sin α+cos αcos α=2cos 2α=2×⎝⎛⎭⎫-352=1825. (2)tan θ=cos 34πsin 34π=-cosπ4sinπ4=-1,又sin3π4>0,cos 3π4<0, 所以θ为第四象限角且θ∈[0,2π),所以θ=7π4.5.(2014·浙江省六市六校高考模拟)函数f (x )=A sin(ωx +φ)(A >0,ω>0,|φ|<π2)的部分图象如图所示,则将y =f (x )的图象向右平移π6个单位长度后,得到的图象解析式为________.6.若函数y =cos 2x +3sin 2x +a 在[0,π2]上有两个不同的零点,则实数a 的取值范围为________.答案 (1)y =sin(2x -π6) (2)(-2,-1]解析 (1)由图知,A =1,3T 4=11π12-π6,故T =π=2πω,所以ω=2,又函数图象过点(π6,1),代入解析式中,得sin(π3+φ)=1,又|φ|<π2,故φ=π6.则f (x )=sin(2x +π6)向右平移π6后,得到y =sin[2(x -π6)+π6)=sin(2x -π6).(2)由题意可知y =2sin(2x +π6)+a ,该函数在[0,π2]上有两个不同的零点,即y =-a ,y =2sin(2x +π6)在[0,π2]上有两个不同的交点.结合函数的图象可知1≤-a <2,所以-2<a ≤-1.7.如图,函数f (x )=A sin(ωx +φ)(其中A >0,ω>0,|φ|≤π2)与坐标轴的三个交点P 、Q 、R 满足P (2,0),∠PQR =π4,M 为QR 的中点,PM =25,则A 的值为________.8.若将函数y =tan(ωx +π4)(ω>0)的图象向右平移π6个单位长度后,与函数y =tan(ωx +π6)的图象重合,则ω的最小正值为________. 答案 (1)1633 (2)12解析 (1)由题意设Q (a,0),R (0,-a )(a >0). 则M (a 2,-a2),由两点间距离公式得,PM =(2-a 2)2+(a 2)2=25,解得a =8,由此得,T 2=8-2=6,即T =12,故ω=π6,由P (2,0)得φ=-π3,代入f (x )=A sin(ωx +φ)得,f (x )=A sin(π6x -π3),从而f (0)=A sin(-π3)=-8,得A =1633.(2)y =tan(ωx +π4)的图象向右平移π6,得到y =tan(ωx +π4-ωπ6)的图象,与y =tan(ωx +π6)重合,得π4-ωπ6=k π+π6,故ω=-6k +12,k ∈Z ,所以ω的最小正值为12. 9.(2014·辽宁改编)将函数y =3sin(2x +π3)的图象向右平移π2个单位长度,所得图象对应的函数的单调增区间为________. 答案 [k π+π12,k π+712π],k ∈Z解析 y =3sin(2x +π3)的图象向右平移π2个单位长度得到y =3sin[2(x -π2)+π3]=3sin(2x -23π).令2k π-π2≤2x -23π≤2k π+π2,k ∈Z ,得k π+π12≤x ≤k π+712π,k ∈Z ,则y =3sin(2x -23π)的单调增区间为[k π+π12,k π+712π],k ∈Z .10.(2014·北京)设函数f (x )=A sin(ωx +φ)(A ,ω,φ是常数,A >0,ω>0).若f (x )在区间⎣⎡⎦⎤π6,π2上具有单调性,且f ⎝⎛⎭⎫π2=f ⎝⎛⎭⎫2π3=-f ⎝⎛⎭⎫π6,则f (x )的最小正周期为________. 答案 π解析 ∵f (x )在⎣⎡⎦⎤π6,π2上具有单调性, ∴T 2≥π2-π6, ∴T ≥2π3.∵f ⎝⎛⎭⎫π2=f ⎝⎛⎭⎫2π3,∴f (x )的一条对称轴为x =π2+2π32=7π12.又∵f ⎝⎛⎭⎫π2=-f ⎝⎛⎭⎫π6, ∴f (x )的一个对称中心的横坐标为π2+π62=π3.∴14T =7π12-π3=π4,∴T =π. 11.已知函数f (x )=sin x +cos x ,g (x )=sin x -cos x ,有下列四个命题: ①将f (x )的图象向右平移π2个单位长度可得到g (x )的图象;②y =f (x )g (x )是偶函数;③f (x )与g (x )均在区间⎣⎡⎦⎤-π4,π4上单调递增; ④y =f (x )g (x )的最小正周期为2π.其中真命题的个数是________. 答案 3解析 f (x )=2sin(x +π4),g (x )=sin x -cos x=2sin(x -π4),显然①正确;函数y =f (x )g (x )=sin 2x -cos 2x =-cos 2x , 其为偶函数,故②正确; 由0≤x +π4≤π2及-π2≤x -π4≤0都可得-π4≤x ≤π4,所以由图象可判断函数f (x )=2sin(x +π4)和函数g (x )=2sin(x -π4)在[-π4,π4]上都为增函数,故③正确;函数y =f (x )g (x )=sin x +cos x sin x -cos x =1+tan x tan x -1=-tan(x +π4),由周期性定义可判断其周期为π,故④不正确.12.如图,为了研究钟表与三角函数的关系,建立如图所示的坐标系,设秒针针尖位置P (x ,y ).若初始位置为P 0⎝⎛⎭⎫32,12,当秒针从P 0(此时t =0)正常开始走时,那么点P 的纵坐标y与时间t 的函数关系为________.答案 y =sin ⎝⎛⎭⎫-π30t +π6 解析 由三角函数的定义可知,初始位置点P 0的弧度为π6,由于秒针每秒转过的弧度为-π30,针尖位置P 到坐标原点的距离为1,故点P 的纵坐标y 与时间t 的函数关系可能为y =sin ⎝⎛⎭⎫-π30t +π6. 13.(2014·四川改编)为了得到函数y =sin(2x +1)的图象,只需把函数y =sin 2x 的图象上所有的点向________平移________个单位长度. 答案 左 12解析 y =sin 2x 的图象向左平移12个单位长度得到函数y =sin 2(x +12)的图象,即函数y =sin(2x +1)的图象.14.函数y =sin(ωx +φ)(ω>0且|φ|<π2)在区间[π6,2π3]上单调递减,且函数值从1减小到-1,那么此函数图象与y 轴交点的纵坐标为____________________________________________. 答案 12解析 依题意知T 2=2π3-π6,所以T =π=2πω,所以ω=2,将点(π6,1)代入y =sin(2x +φ)得sin(π3+φ)=1,又|φ|<π2,φ=π6,故y =sin(2x +π6),与y 轴交点纵坐标为12.15.若函数y =A sin(ωx +φ)(A >0,ω>0,|φ|<π2)在一个周期内的图象如图所示,M ,N 分别是这段图象的最高点与最低点,且OM →·ON →=0,则A ·ω=________.答案7π6解析 由题中图象知T 4=π3-π12,所以T =π,所以ω=2. 则M ⎝⎛⎭⎫π12,A ,N ⎝⎛⎭⎫7π12,-A 由OM →·ON →=0,得7π2122=A 2,所以A =7π12,所以A ·ω=7π6. 16.已知函数f (x )=sin(2x +φ),其中|φ|<π,若f (x )≤|f (π6)|对x ∈R 恒成立,且f (π2)<f (π),则下列结论正确的是________. ①f (1112π)=-1;②f (7π10)>f (π5);③f (x )是奇函数;④f (x )的单调递增区间是[k π-π3,k π+π6](k ∈Z ).答案 ④解析 由f (x )≤|f (π6)|恒成立知x =π6是函数的对称轴,即2×π6+φ=π2+k π,k ∈Z ,所以φ=π6+k π,k ∈Z ,又f (π2)<f (π),所以sin(π+φ)<sin(2π+φ),即-sin φ<sin φ.所以sin φ>0,得φ=π6,即f (x )=sin(2x +π6),由-π2+2k π≤2x +π6≤π2+2k π,k ∈Z ,得-π3+k π≤x ≤π6+k π,k ∈Z ,即函数的单调递增区间是[k π-π3,k π+π6](k ∈Z ).17.已知A ,B ,C ,D ,E 是函数y =sin(ωx +φ)(ω>0,0<φ<π2)一个周期内的图象上的五个点,如图所示,A (-π6,0),B 为y 轴上的点,C 为图象上的最低点,E 为该函数图象的一个对称中心,B 与D 关于点E 对称,CD →在x 轴上的投影为π12,则ω,φ的值分别为________________________________________________________________________.答案 2,π3解析 因为A ,B ,C ,D ,E 是函数y =sin(ωx +φ)(ω>0,0<φ<π2)一个周期内的图象上的五个点,A (-π6,0),由题意得T =4×(π12+π6)=π,所以ω=2,因为A (-π6,0),所以f (-π6)=sin(-π3+φ)=0,0<φ<π2,φ=π3.18.(2014·安徽)若将函数f (x )=sin(2x +π4)的图象向右平移φ个单位长度,所得图象关于y 轴对称,则φ的最小正值是________. 答案3π8解析 ∵函数f (x )=sin(2x +π4)的图象向右平移φ个单位长度得到g (x )=sin[2(x -φ)+π4]=sin(2x +π4-2φ),又∵g (x )是偶函数,∴π4-2φ=k π+π2(k ∈Z ).∴φ=-k π2-π8(k ∈Z ).当k =-1时,φ取得最小正值3π8.19.函数f (x )=A sin(ωx +φ)(A >0,ω>0,|φ|<π2)的部分图象如图所示,若x 1,x 2∈(-π6,π3),且f (x 1)=f (x 2),则f (x 1+x 2)=________.答案32解析 观察图象可知,A =1,T =π,所以ω=2, f (x )=sin(2x +φ).将(-π6,0)代入上式得sin(-π3+φ)=0,由已知得φ=π3,故f (x )=sin(2x +π3).函数图象的对称轴为x =-π6+π32=π12.又x 1,x 2∈(-π6,π3),且f (x 1)=f (x 2),∴f (x 1+x 2)=f (2×π12)=f (π6)=sin(2×π6+π3)=32.20.已知函数f (x )=3sin(ωx -π6)(ω>0)和g (x )=3cos(2x +φ)的图象的对称中心完全相同,若x ∈[0,π2],则f (x )的取值范围是________.答案 [-32,3]解析 由两三角函数图象的对称中心完全相同,可知两函数的周期相同,故ω=2,所以f (x )=3sin(2x -π6),那么当x ∈[0,π2]时,-π6≤2x -π6≤5π6,所以-12≤sin(2x -π6)≤1,故f (x )∈[-32,3].21.给出命题:①函数y =2sin(π3-x )-cos(π6+x )(x ∈R )的最小值等于-1;②函数y =sin πx cosπx 是最小正周期为2的奇函数;③函数y =sin(x +π4)在区间[0,π2]上单调递增的;④若sin 2α<0,cos α-sin α<0,则α一定为第二象限角.则真命题的序号是________.答案 ①④解析 对于①,函数y =2sin(π3-x )-cos(π6+x )=sin(π3-x ),所以其最小值为-1;对于②,函数y =sin πx cos πx =12sin 2πx 是奇函数,但其最小正周期为1;对于③,函数y =sin(x +π4)在区间[0,π4]上单调递增,在区间[π4,π2]上单调递减;对于④,由⎩⎪⎨⎪⎧sin 2α<0,cos α-sin α<0⇒cos α<0,sin α>0,所以α一定为第二象限角.二、解答题11.已知函数f (x )=A sin(3x +φ)(A >0,x ∈(-∞,+∞),0<φ<π)在x =π12时取得最大值4.(1)求f (x )的最小正周期; (2)求f (x )的解析式;(3)若f (23α+π12)=125,求sin α.解 (1)f (x )的最小正周期T =2π3. (2)由函数的最大值为4,可得A =4. 所以f (x )=4sin(3x +φ).当x =π12时,4sin(3×π12+φ)=4,所以sin(π4+φ)=1,所以φ=2k π+π4,k ∈Z ,因为0<φ<π,所以φ=π4.所以f (x )的解析式是f (x )=4sin(3x +π4).(3)因为f (23α+π12)=125,故sin(2α+π4+π4)=35.所以cos 2α=35,即1-2sin 2α=35,故sin 2α=15.所以sin α=±55.12.设函数f (x )=sin 2ωx +23sin ωx ·cos ωx -cos 2ωx +λ(x ∈R )的图象关于直线x =π对称,其中ω,λ为常数,且ω∈(12,1).(1)求函数f (x )的最小正周期;(2)若y =f (x )的图象经过点(π4,0),求函数f (x )在x ∈[0,π2]上的值域.解 (1)因为f (x )=sin 2ωx +23sin ωx ·cos ωx -cos 2ωx +λ=-cos 2ωx +3sin 2ωx +λ=2sin(2ωx -π6)+λ,由直线x =π是y =f (x )图象的一条对称轴,可得 sin(2ωπ-π6)=±1,所以2ωπ-π6=k π+π2(k ∈Z ),即ω=k 2+13(k ∈Z ).又ω∈(12,1),k ∈Z ,所以k =1,故ω=56.所以f (x )的最小正周期是6π5.(2)由y =f (x )的图象过点(π4,0),得f (π4)=0,即λ=-2sin(56×π2-π6)=-2sin π4=-2,即λ=- 2.故f (x )=2sin(53x -π6)-2,∵x ∈[0,π2],∴53x -π6∈[-π6,2π3],∴函数f (x )的值域为[-1-2,2-2].热点三 三角函数的性质例3 设函数f (x )=2cos 2x +sin 2x +a (a ∈R ). (1)求函数f (x )的最小正周期和单调递增区间;(2)当x ∈[0,π6]时,f (x )的最大值为2,求a 的值,并求出y =f (x )(x ∈R )的对称轴方程.思维启迪 先化简函数解析式,然后研究函数性质(可结合函数简图). 解 (1)f (x )=2cos 2x +sin 2x +a =1+cos 2x +sin 2x +a =2sin(2x +π4)+1+a ,则f (x )的最小正周期T =2π2=π,且当2k π-π2≤2x +π4≤2k π+π2(k ∈Z )时f (x )单调递增,即k π-38π≤x ≤k π+π8(k ∈Z ).所以[k π-3π8,k π+π8](k ∈Z )为f (x )的单调递增区间.(2)当x ∈[0,π6]时⇒π4≤2x +π4≤7π12, 当2x +π4=π2,即x =π8时,sin(2x +π4)=1. 所以f (x )max =2+1+a =2⇒a =1- 2.由2x +π4=k π+π2,得x =k π2+π8(k ∈Z ), 故y =f (x )的对称轴方程为x =k π2+π8,k ∈Z . 思维升华 函数y =A sin(ωx +φ)的性质及应用的求解思路:第一步:先借助三角恒等变换及相应三角函数公式把待求函数化成y =A sin(ωx +φ)+B 的形式;第二步:把“ωx +φ”视为一个整体,借助复合函数性质求y =A sin(ωx +φ)+B 的单调性及奇偶性、最值、对称性等问题.已知函数f (x )=2sin ωx cos ωx +23sin 2ωx -3(ω>0)的最小正周期为π.(1)求函数f (x )的单调增区间;(2)将函数f (x )的图象向左平移π6个单位长度,再向上平移1个单位长度,得到函数y =g (x )的图象;若y =g (x )在[0,b ](b >0)上至少含有10个零点,求b 的最小值.解 (1)由题意得f (x )=2sin ωx cos ωx +23sin 2ωx - 3=sin 2ωx -3cos 2ωx =2sin(2ωx -π3), 由周期为π,得ω=1,得f (x )=2sin(2x -π3), 函数的单调增区间为2k π-π2≤2x -π3≤2k π+π2,k ∈Z , 整理得k π-π12≤x ≤k π+5π12,k ∈Z , 所以函数f (x )的单调增区间是[k π-π12,k π+5π12],k ∈Z . (2)将函数f (x )的图象向左平移π6个单位长度,再向上平移1个单位长度,得到y =2sin 2x +1的图象,所以g (x )=2sin 2x +1,令g (x )=0,得x =k π+7π12或x =k π+11π12(k ∈Z ), 所以在[0,π]上恰好有两个零点,若y =g (x )在[0,b ]上有10个零点,则b 不小于第10个零点的横坐标即可,即b 的最小值为4π+11π12=59π12. 2.已知函数f (x )=sin ωx ·cos ωx +3cos 2ωx -32(ω>0),直线x =x 1,x =x 2是y =f (x )图象的任意两条对称轴,且|x 1-x 2|的最小值为π4. (1)求f (x )的表达式;(2)将函数f (x )的图象向右平移π8个单位长度后,再将得到的图象上各点的横坐标伸长为原来的2倍,纵坐标不变,得到函数y =g (x )的图象,若关于x 的方程g (x )+k =0在区间[0,π2]上有且只有一个实数解,求实数k 的取值范围.解 (1)f (x )=12sin 2ωx +3×1+cos 2ωx 2-32=12sin 2ωx +32cos 2ωx =sin(2ωx +π3), 由题意知,最小正周期T =2×π4=π2, T =2π2ω=πω=π2,所以ω=2,所以f (x )=sin ⎝⎛⎭⎫4x +π3. (2)将f (x )的图象向右平移π8个单位长度后,得到y =sin(4x -π6)的图象, 再将所得图象所有点的横坐标伸长到原来的2倍,纵坐标不变,得到y =sin(2x -π6)的图象.所以g (x )=sin(2x -π6). 令2x -π6=t ,因为0≤x ≤π2,所以-π6≤t ≤5π6. g (x )+k =0在区间[0,π2]上有且只有一个实数解, 即函数g (t )=sin t 与y =-k 在区间[-π6,5π6]上有且只有一个交点.如图,由正弦函数的图象可知-12≤-k <12或-k =1. 所以-12<k ≤12或k =-1.。
2016-2017学年度上学期高三年级六调考试理数试卷 第Ⅰ卷一、选择题:本大题共12个小题,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。
1。
已知21zi i=++,则复数z =( )A .13i -B . 13i --C .13i -+D .13i +2。
已知命题()()()()122121:,,0p x xR f x f x x x ∀∈--≥,则p ⌝是()A .()()()()122121,,0x xR f x f x x x ∃∉--<B . ()()()()122121,,0x x R f x f x x x ∃∈--<C .()()()()122121,,0x x R f x f x x x ∀∉--<D .()()()()122121,,0x xR f x f x x x ∀∈--<3.已知()f x 是奇函数,且()()2f x f x -=,当[]2,3x ∈时,()()2log 1f x x =-,则13f ⎛⎫= ⎪⎝⎭( ) A .22log 3-B . 22log 3log 7-C .22log7log 3-D .2log32-4.直线3y kx =+与圆()()22234x y -+-=相交于,M N 两点,若MN ≥则k 的取值范围是 ( )A .3,04⎡⎤-⎢⎥⎣⎦B .2,03⎡⎤-⎢⎥⎣⎦C.⎡⎣ D .⎡⎢⎣5.如图,若4n =时,则输出的结果为( )A .37B . 67C 。
49D .5116.已知一个底面为正六边形,侧棱长都相等的六棱锥的正视图与俯视图如图所示,若该几何体的底面边长为2,侧棱长为7,则该几何体的侧视图可能是 ( )A .B .C 。
D .7。
已知,A B 为双曲线E 的左,右顶点,点M 在E 上,ABM ∆为等腰三角形,且顶角为120°,则E 的离心率为 ( ) A . 2 B .2 C. 3 D 58.已知,x y 满足约束条件102202x y x y y -+≥⎧⎪-+≤⎨⎪≤⎩,则23z x y =-的最小值为()A . -6B .—3C 。
一.基础题组1。
【湖南省长沙市长郡中学2017届高三摸底考试数学(理)试题】已知等差数列{}na 的前n 项和nS 满足350,5SS ==,数列21211{}n n a a -+的前2016项的和为 。
【答案】20164031-考点:等差数列的通项公式,裂项相消法求和.2. 【江西省新余市第一中学2017届高三上学期调研考试(一)(开学考试)】已知等比数列{}na 中,262,8a a ==,则345a a a =( )A .64±B .64C .32D .16 【答案】B 【解析】试题分析:由等比数列的性质可知226416a a a ⋅==,而246,,a a a 同号,故44a =,所以3345464a a a a ==. 考点:等比数列的性质.3。
【江西省新余市第一中学2017届高三上学期调研考试(一)(开学考试)】 数列{}na 满足()121112n n an N a a *+=+=∈,记212n n n b a =,则数列{}nb 的前n 项和nS = .【答案】2332nn +-【解析】 试题分析:11n a +=得221112n n a a +-=,且2111a =,所以数列21n a ⎧⎫⎨⎬⎩⎭构成以1为首项,2为公差的等差数列,所以211(1)221nn n a =+-⨯=-,从而得到2121n a n =-,则212nnn b-=, 所以21321222nn n S-=+++,231113232122222nn n n n S +--=++++, 两式相减,得2111111121222222n n n n S -+-=++++-1111121323122222n n n n n -++-+=+--=- 所以2332nnn S+=-. 考点:错位相减法求和.【名师点睛】利用错位相减法求数列的前n 项和时,应注意两边乘公比后,对应项的幂指数会发生变化,为避免出错,应将相同幂指数的项对齐,这样有一个式子前面空出一项,另外一个式子后面就会多了一项,两式相减,除第一项和最后一项外,剩下的1n -项是一个等比数列.4。
2017届高考英语专题练习(六)阅读理解Ⅳ:词义猜测(测)1.B【甘肃省兰州市第一中学2017届高三上学期期中考试】An 80-year-old man was sitting on the sofa in his house along with his 45-year-old highly educated son.Suddenly a crow perched on the tree near their window.The father asked his son, “What is this?”The son replied, “It is a crow.”After a few minutes, the father asked his son the second time, “What is this?”The son said, “Father, I have just now told you. It is a crow!”After a little while, the old father again asked his son the third time, “What is this?”“It’ s a crow, a crow, a crow!” said the son loudly.A little after, the father again asked his son the fourth time, “What is this?”This time the son shouted at his father, “Why do you keep asking me the same question again and again?’ IT IS A CROW’. Are you not able to understand this?”A little later the father went to his room and came back with an old diary, which he had kept since his son was born. On opening a page, he asked his son to read that page. When the son read it, the following words were written in the diary:“Today my little son aged three was sitting with me on the sofa, when a crow was sitting on the window. My son asked me 23times what it was, and I replied to him all 23times that it was crow. I hugged him lovingly each time he asked me the same question again and again for 23times. I did not at all feel annoyed; I rather felt affection for my innocent child.”5.What does the underlined word “perched” mean in the passage?A.knocked B.hitC.landed D.flew2.C【湖北省华中师范大学第一附属中学2017届高三上学期期中考试】BEIJING—The launch of a new manned space mission brings China closer to the establishment of a permanent space station, international experts say.Chinese taikonauts, Jing Haipeng, 50, and Chen Dong, 37, were blasted off into space onboard Shenzhou-11 at 7:30 am Monday and will spend 30 days in the Chinese space laboratory Tiangong-2. The launch marks a key step toward China's plan to eventually operate a permanent space station, The successful launch of the Shenzhou-11 spacecraft is another step forward to put China among leading players in space technology, said Alexander Zheleznyakov, a Russian expert on history of space flights. China's experimental space lab will help provide solutions for spacecraft of different functions to approach and anchor, and for a long-term operation of life support system, said Zheleznyakov. Shenzhou-11 is scheduled to anchor on Wednesday with Tiangong-2, which is part of China's plan to build a permanent space station by 2022.China can now test technologies for cargo spacecraft anchoring, life support system operation and waterrecycling to ensure a long-term continuous operation of its space station in the future with less dependence on renewal from the Earth, he said. If all goes well, China will launch the unpiloted Tianzhou-1cargo ship next spring to autonomously tie up with Tiangong-2. Tianzhou-1will be capable of automatically transferring rocket fuels, a vital requirement for space station grouping and maintenance, according to a report by Columbia Broadcasting System(CBS).“That will further their anchoring abilities needed for the larger space station,” Johnson Freese was quoted. “Tiangong-2 is supposed to be able to stay in orbit for two years or longer, so that's taking them (Chinese)really close to 2019 or so. I think this will be their last big technology test phase before going to their large space station,” said Freese.31.Which of the following can repl ace the underlined phrase “blasted off” in last paragraph?A.sent up B.gave away C.swept off D.carried away3.B【山东省枣庄市第三中学2017届高三9月质量检测】It has always been thought that alcohol causes people to put on weight because it contains a lot of sugar, but new research suggests a glass a day cold form part of a diet. Looking at past studies they found that, while heavy drinkers do put on weight; those who drink in moderation can actually lose weight.A spokesman for the research team at Navarro University in S pain says, “Light to moderate alcohol intake, especially of wine, may be more likely to protect against, rather than promote, weight gain.” The International Scientific Forum on Alcohol research reviewed the findings and agreed with most of the conclusions, particularly that data do not clearly indicate if moderate drinking increases weight.Boston University’s Dr. Harvey Finkel found that the biologic mechanisms(生物学机制)relating alcohol to changes in body weight are not properly understood. His team pointed out the strong protective effects of moderate drinking on the risk of getting conditions like diabetes(糖尿病), which relate to increasing obesity. Some studies suggest that even very obese people may be at lower risk of diabetes if they are moderate drinkers.The group says alcohol provides calories that are quickly absorbed into the body and are not stored in fat, and that this process could explain the differences in its effects from those of other foods. They agree that future research should be directed towards assessing the roles of different types of alcoholic drinks, taking into consideration drinking patterns and including the past tendency of participants to gain weight.For now there is little evidence that consuming small to moderate amounts of alcohol on a regular basis increases one’s risk of becoming obese. What’s more, a study three years ago suggested that resveratrol, a compound present in grapes and red wine destroys fat cells.25.The underlined phrase “in moderation” in the first paragraph me ans_________.A.excitedly B.carefully C.frequently D.properly4.【黑龙江省大庆实验中学2017届高三上学期期中考试】One form of social prejudice against older people is the belief that they cannot understand or use modern technology. Activities like playing computer games, going on the Net and downloading MP3s are only for the youngsters. Isn’t it unfair that older people enjoying a computer game should be frowned(皱眉)upon by their children and grandchildren?Nowadays older people have more control over their lives and they play a full part in society. Moreover, better health care has left more people in their sixties and seventies feeling fit and active after retirement. Mental activity, as well as physical exercise, can contribute to better health. Playing computer games is a very effective way of exercising the brain.When personal computers were first introduced, most older people didn’t believe they would ever familiarize themselves with it. Now computers have been around for a few generations and retired people have gradually become more relaxed about using them for fun. Gamers over 65 prefer playing puzzle games and card games. Kate Stevens, aged 72, says:“I find it very relaxing. It’s not very demanding, but you still need to concentrate.”Another development that has f avored “grey games” is a change in the type of videogames available on the market. There’s a greater variety of games to choose from, including more intellectual and complex strategy(策略)and simulation(模拟)games. Internet Chess and Train Simulator are among the most popular of these. Train Simulator is based on real-world rail activities. Players can choose from a variety of challenges, such as keeping to a strict-timetable and using helper engines during a winter storm.Some people argue that “grey gamers” simply don’t have the skills required for computer games, and that teenagers are better. This couldn’t be further from the truth. Most computer games require the kind of analytical thinking that improves with practice, which means that the “grey gamers” may well be far better than gamers half a century younger than them. In games where speed is the main consideration, older people would be at a disadvantage because they may have slower reaction times. On the other hand, “grey gamers” have a preference for slower paced, mind challenging games.4.By saying “This couldn’t be further from the truth.” in Paragraph 5, the author means_________.A.mind challenging games are not suitable for older peopleB.children should improve their skills with practiceC.playing computer games requires analytical thinkingD.older people can perform well in some computer games5.【黑龙江省双鸭山市第一中学2017届高三9月月考】One day a mime(哑剧演员)is visiting the zoo and tries to earn some money as a street performer. As soon as he starts to draw a crowd, a zookeeper pulls him into his office. The zookeeper explains that the zoo’s most popular attraction, a gorilla(大猩猩), has died suddenly and the keeper fears that attendance(出席人数)at the zoo will fall off. He offers the mime a job to dress up as the gorilla. The mime accepts.The next morning the mime puts on the gorilla suit and enters the cage before the crowd comes. He soon discovers he can sleep, play and make fun of people and he draws bigger crowds than he ever did as a mime — the job he likes but loses.However, with days going by, he begins to notice that the people are paying more attention to the lion in the cage next to his. Not wanting to lose the attention of his audience, he climbs to the top of his cage, crawls across a partition(隔墙), and dangles(悬挂)from the top to the lion’s cage. The lion gets angry at this. The scene is a fuel to the crowd.At the end of the day he is given a raise for being such a good attraction — well, this continues for some time. The crowds grow larger, and th e mime’s pay keeps going up.Then one day when he is dangling over the lion he slides and falls. The mime is terrified. He starts screaming “Help me!”, but the lion is quick. The mime soon finds himself flat on his back looking up at the angry lion and th e lion says, “Shut up you fool! Do you want to get us both fired?”24.The underlined words “a fuel” in Paragraph 3can be replaced by __________.A.frightening B.disappointing C.familiar D.exciting高考英语专题练习(六)阅读理解Ⅳ:词义猜测题(测)解析1.2.3.4.5.。
2017届高三强化班提优练习六1.已知sin(α+π3)+sin α=-435,-π2<α<0,则cos(α+2π3)=________. 2.(2014·课标全国Ⅰ)设α∈(0,π2),β∈(0,π2),且tan α=1+sin βcos β,则2α-β=________. 答案 (1)45 (2)π2解析 (1)∵sin(α+π3)+sin α=-435,-π2<α<0, ∴32sin α+32cos α=-435, ∴32sin α+12cos α=-45, ∴cos(α+2π3)=cos αcos 2π3-sin αsin 2π3=-12cos α-32sin α=45. (2)由tan α=1+sin βcos β得sin αcos α=1+sin βcos β, 即sin αcos β=cos α+cos αsin β,∴sin(α-β)=cos α=sin(π2-α). ∵α∈(0,π2),β∈(0,π2), ∴α-β∈(-π2,π2),π2-α∈(0,π2), ∴由sin(α-β)=sin(π2-α),得α-β=π2-α, ∴2α-β=π2.3.△ABC 的三个内角A ,B ,C 所对的边分别为a ,b ,c ,a sin A sin B +b cos 2A =2a ,则b a=________.4.(2014·江西改编)在△ABC 中,内角A ,B ,C 所对的边分别是a ,b ,c .若c 2=(a -b )2+6,C =π3,则△ABC 的面积是________. 答案 (1)2 (2)323 解析 (1)因为a sin A sin B +b cos 2A =2a ,由正弦定理得sin 2A sin B +sin B cos 2A =2sin A ,即sin B =2sin A ,即sin B sin A =2,b a =sin B sin A = 2. (2)∵c 2=(a -b )2+6,∴c 2=a 2+b 2-2ab +6.①∵C =π3,∴c 2=a 2+b 2-2ab cos π3=a 2+b 2-ab .② 由①②得ab =6.∴S △ABC =12ab sin C =12×6×32=332. 5.(2013·浙江改编)已知α∈R ,sin α+2cos α=102,则tan 2α=________. 答案 -34解析 ∵sin α+2cos α=102, ∴sin 2α+4sin α·cos α+4cos 2α=52. 用降幂公式化简得:4sin 2α=-3cos 2α,∴tan 2α=sin 2αcos 2α=-34. 6.(2014·江苏)若△ABC 的内角满足sin A +2sin B =2sin C ,则cos C 的最小值是________. 答案 6-24解析 由sin A +2sin B =2sin C ,结合正弦定理得a +2b =2c .由余弦定理得cos C =a 2+b 2-c 22ab=a 2+b 2-(a +2b )242ab =34a 2+12b 2-2ab 22ab ≥2⎝⎛⎭⎫34a 2⎝⎛⎭⎫12b 2-2ab 22ab =6-24, 故6-24≤cos C <1,且3a 2=2b 2时取“=”. 故cos C 的最小值为6-24. 7.在△ABC 中,已知tanA +B 2=sinC ,给出以下四个结论: ①tan A tan B=1;②1<sin A +sin B ≤2;③sin 2A +cos 2B =1;④cos 2A +cos 2B =sin 2C .其中一定正确的是________.答案 ②④解析 依题意,tan A +B 2=sinA +B 2cos A +B 2=2sin A +B 2cos A +B 22cos 2A +B 2 =sin (A +B )1+cos (A +B )=sinC 1+cos (A +B )=sin C . ∵sin C ≠0,∴1+cos(A +B )=1,cos(A +B )=0.∵0<A +B <π,∴A +B =π2,即△ABC 是以角C 为直角的直角三角形. 对于①,由tan A tan B=1,得tan A =tan B ,即A =B ,不一定成立,故①不正确; 对于②,∵A +B =π2,∴sin A +sin B =sin A +cos A =2sin(A +π4), ∴1<sin A +sin B ≤2,故②正确;对于③,∵A +B =π2,∴sin 2A +cos 2B =sin 2A +sin 2A =2sin 2A , 其值不确定,故③不正确;对于④,∵A +B =π2,∴cos 2A +cos 2B =cos 2A +sin 2A =1=sin 2C ,故④正确. 8.(2014·浙江改编)为了得到函数y =sin 3x +cos 3x 的图象,可以将函数y =2cos 3x 的图象向________平移________个单位.答案 右 π12解析 因为y =sin 3x +cos 3x =2sin(3x +π4) =2sin[3(x +π12)],又y =2cos 3x =2sin(3x +π2) =2sin[3(x +π6)],所以应由y =2cos 3x 的图象向右平移π12个单位得到. 9.(2014·无锡质检)已知α∈(π2,π),sin(α+π4)=35,则cos α=________. 答案 -210解析 ∵α∈(π2,π).∴α+π4∈(34π,54π). ∵sin(α+π4)=35, ∴cos(α+π4)=-45,∴cos α=cos(α+π4-π4)=cos(α+π4)cos π4+sin(α+π4)sin(π4)=-45×22+35×22=-210. 10.在△ABC 中,若sin C sin A =3,b 2-a 2=52ac ,则cos B 的值为________. 答案 14解析 由正弦定理得c a =sin C sin A=3, 由余弦定理得cos B =a 2+c 2-b 22ac =c 2-52ac 2ac =12×c a -54=32-54=14. 11.(2013·陕西改编)设△ABC 的内角A ,B ,C 所对的边分别为a ,b ,c ,若b cos C +c cos B =a sin A ,则△ABC 的形状为________.答案 直角三角形解析 由b cos C +c cos B =a sin A ,得sin B cos C +sin C cos B =sin 2A ,即sin(B +C )=sin 2A ,所以sin A =1,由0<A <π,得A =π2,所以△ABC 为直角三角形. 12.已知tan β=43,sin(α+β)=513,其中α,β∈(0,π),则sin α的值为________. 答案 6365解析 依题意得sin β=45,cos β=35.注意到sin(α+β)=513<sin β,因此有α+β>π2(否则,若α+β≤π2,则有0<β<α+β≤π2,0<sin β<sin(α+β),这与“sin(α+β)<sin β”矛盾),则cos(α+β)=-1213,sin α=sin [(α+β)-β]=sin(α+β)cos β-cos(α+β)sin β=6365. 13.已知△ABC 中,角A 、B 、C 的对边分别是a 、b 、c ,且tan B =2-3a 2-b 2+c2,BC →·BA →=12,则tan B 等于________.答案 2- 3解析 由题意得,BC →·BA →=|BC →|·|BA →|cos B=ac cos B =12,即cos B =12ac, 由余弦定理, 得cos B =a 2+c 2-b 22ac =12ac⇒a 2+c 2-b 2=1, 所以tan B =2-3a 2-b 2+c2=2- 3.14.已知tan ⎝⎛⎭⎫α+π4=12,且-π2<α<0,则2sin 2α+sin 2αcos ⎝⎛⎭⎫α-π4=________. 答案 -255解析 由tan ⎝⎛⎭⎫α+π4=tan α+11-tan α=12, 得tan α=-13. 又-π2<α<0,可得sin α=-1010. 故2sin 2α+sin 2αcos ⎝⎛⎭⎫α-π4=2sin α(sin α+cos α)22(sin α+cos α) =22sin α=-255. 15.在△ABC 中,内角A 、B 、C 的对边长分别为a 、b 、c ,已知a 2-c 2=2b ,且sin A cos C =3cos A sin C ,则b =________.答案 4解析 由sin A cos C =3cos A sin C 得a 2R ·a 2+b 2-c 22ab =3·b 2+c 2-a 22bc ·c 2R , 所以a 2+b 2-c 2=3(b 2+c 2-a 2),a 2-c 2=b 22, 解方程组⎩⎪⎨⎪⎧a 2-c 2=2b a 2-c 2=b 22,得b =4. 16.已知0<α<π2<β<π,cos(β-π4)=13,sin(α+β)=45,则cos(α+π4)=________. 答案 82-315 解析 因为0<α<π2<β<π, 所以π4<β-π4<3π4,π2<α+β<3π2. 所以sin(β-π4)>0,cos(α+β)<0. 因为cos(β-π4)=13,sin(α+β)=45, 所以sin(β-π4)=223,cos(α+β)=-35. 所以cos(α+π4)=cos[(α+β)-(β-π4)]=cos(α+β)cos(β-π4)+sin(α+β)sin(β-π4) =-35×13+45×223=82-315. 17.如图,嵩山上原有一条笔直的山路BC ,现在又新架设了一条索道AC ,小李在山脚B 处看索道AC ,发现张角∠ABC 为120°;从B 处攀登400米到达D 处,回头看索道AC ,发现张角∠ADC 为150°;从D 处再攀登800米方到达C 处,则索道AC 的长为________米.答案 40013解析 如题图,在△ABD 中,BD =400米,∠ABD =120°.因为∠ADC =150°,所以∠ADB =30°.所以∠DAB =180°-120°-30°=30°.由正弦定理,可得BD sin ∠DAB =AD sin ∠ABD . 所以400sin 30°=AD sin 120°,得AD =4003(米). 在△ADC 中,DC =800米,∠ADC =150°,由余弦定理,可得AC 2=AD 2+CD 2-2×AD ×CD ×cos ∠ADC=(4003)2+8002-2×4003×800×cos 150°=4002×13,解得AC =40013(米). 故索道AC 的长为40013米.18.设函数f (x )=cos(2x +π3)+sin 2x . (1)求函数f (x )的最小正周期和最大值; (2)若θ是第二象限角,且f (θ2)=0,求cos 2θ1+cos 2θ-sin 2θ的值. 解 (1)f (x )=cos(2x +π3)+sin 2x =cos 2x cos π3- sin 2x sin π3+1-cos 2x 2=12-32sin 2x . 所以f (x )的最小正周期为T =2π2=π,最大值为1+32. (2)因为f (θ2)=0, 所以12-32sin θ=0,即sin θ=33, 又θ是第二象限角,所以cos θ=-1-sin 2θ=-63.所以cos 2θ1+cos 2θ-sin 2θ=cos 2θ-sin 2θ2cos 2θ-2sin θcos θ=(cos θ+sin θ)(cos θ-sin θ)2cos θ(cos θ-sin θ)=cos θ+sin θ2cos θ =-63+332×(-63)=6-326=2-24. 19.在△ABC 中,角A ,B ,C 所对的边分别为a ,b ,c ,满足a =2sin A ,cos B cos C +2a c +b c=0. (1)求边c 的大小;(2)求△ABC 面积的最大值.思维启迪 (1)将cos B cos C +2a c +b c=0中的边化成角,然后利用和差公式求cos C ,进而求c .(2)只需求ab 的最大值,可利用cos C =a 2+b 2-c 22ab和基本不等式求解. 解 (1)∵cos B cos C +2a c +b c=0, ∴c cos B +2a cos C +b cos C =0,∴sin C cos B +sin B cos C +2sin A cos C =0,∴sin A +2sin A cos C =0,∵sin A ≠0,∴cos C =-12,∵C ∈(0,π),∴C =2π3, ∴c =a sin A·sin C = 3. (2)∵cos C =-12=a 2+b 2-32ab, ∴a 2+b 2+ab =3,∴3ab ≤3,即ab ≤1.∴S △ABC =12ab sin C ≤34. ∴△ABC 面积的最大值为34.19.已知角A 、B 、C 是△ABC 的三个内角,若向量m =(1-cos(A +B ),cos A -B 2),n =(58,cos A -B 2),且m ·n =98. (1)求tan A tan B 的值;(2)求ab sin C a 2+b 2-c 2的最大值. 解 (1)m ·n =58-58cos(A +B )+cos 2A -B 2=98-18cos A cos B +98sin A sin B =98, ∴cos A cos B =9sin A sin B ,得tan A tan B =19. (2)tan(A +B )=tan A +tan B 1-tan A tan B =98(tan A +tan B )≥982tan A tan B =34.(∵tan A tan B =19>0, ∴A ,B 均是锐角,即其正切值均为正)ab sin C a 2+b 2-c 2=sin C 2cos C =12tan C =-12tan(A +B )≤-38,所求最大值为-38. 20.在△ABC 中,角A ,B ,C 所对的边分别为a ,b ,c ,q =(2a,1),p =(2b -c ,cos C ),且q ∥p .(1)求sin A 的值;(2)求三角函数式-2cos 2C 1+tan C+1的取值范围. 解 (1)∵q =(2a,1),p =(2b -c ,cos C )且q ∥p ,∴2b -c =2a cos C ,由正弦定理得2sin A cos C =2sin B -sin C ,又sin B =sin(A +C )=sin A cos C +cos A sin C ,∴12sin C =cos A sin C . ∵sin C ≠0,∴cos A =12,又∵0<A <π,∴A =π3,∴sin A =32. (2)原式=-2cos 2C 1+tan C +1=1-2(cos 2C -sin 2C )1+sin C cos C=1-2cos 2C +2sin C cos C =sin 2C -cos 2C =2sin(2C -π4), ∵0<C <23π,∴-π4<2C -π4<1312π,∴-22<sin(2C -π4)≤1, ∴-1<2sin(2C -π4)≤2, 即三角函数式-2cos 2C 1+tan C+1的取值范围为(-1,2].。
成⼈英语三级考试频道为⼤家推出【】考⽣可点击以下⼊⼝进⼊免费试听页⾯!⾜不出户就可以边听课边学习,为⼤家的梦想助⼒!2017年成⼈学位英语考试阅读理解强化练习及答案六 Chokwe Selassie is on a mission to help drivers avoid potholes(路⾯坑洼).The eighth-grader was inspired to kick off his mission on a recent morning, when his mother was driving him to school. Their car was damaged as it went over a huge pothole in the middle of the street in their hometown of Jackson, Mississippi. "I decided I was going to do something about the pothole problem in my city," Chokwe says. His solution: an app that warns drivers when there is a pothole ahead. Chokwe developed the app with his friends Rodriguez Ratliff and Emmanuel Brooks. "When the app detects a pothole, it is highlighted(突出显⽰)in red," Chokwe says. "And if you get close to the pothole, your phone will warn you." Drivers can also use the app to report any potholes they encounter, and to look for other routes they can take to avoid roads that have them. The app relies on current available information about the streets of Jackson. "It works by using the city's 311 call system, soit uses information already stored in a database," Chokwe says. (79) Throughthe call system, citizens dial 3-1-1 to report non-emergency problems—which include potholes. Chokwe and his friends determined that focusing on the 10 busiest streets in Jackson would give them a large enough sample size to test th prototype(原型). (80) Although the app isn't yet available for sale,Chokwe is already looking for ways to improve it. The prototype remains limited to 10 streets in Jackson, but he hopes to add more, so that it includes every street in the city. And then he wants to go even farther. “I want to keep working on the app until it's nationwide,” Chokwe says. 1. Which of the following is the best title for the passage? A. A Solution to Traffic Jams B. An App to Detect Potholes C. Pothole Problems in Big Cities D. Poor Road Conditions 答案解析: Which of the following is the best title for the passage?(下⾯哪个选项是⽂章最合适的标题?) 答案为B(an APP to detect potholes(检测路⾯有坑洼的APP)) 答题思路:利⽤⽂章主题词直接判断答案。
提升考能、阶段验收专练卷(一)集合与常用逻辑用语、函数、导数及其应用(时间:80分钟 满分:120分)Ⅰ.小题提速练(限时35分钟)填空题(本大题共12小题,每小题5分,共60分)1.(2016·苏州名校联考)若集合A ={}x |1≤3x≤81,B ={}x |log 2x 2-x,则A ∩B=________.解析:因为A ={}x |1≤3x≤81={}x |30≤3x ≤34={}x |0≤x ≤4,B ={}x |log 2x 2-x ={}x |x 2-x >2={}x |x <-1或x >2,所以A ∩B ={}x |0≤x ≤4∩{}x |x <-1或x >2={}x |2<x ≤4=(2,4]. 答案:(2,4]2.(2016·无锡调研)若f (x )=⎩⎪⎨⎪⎧-x ,x ≤0,x 2-2x ,x >0,则f (x )的最小值是________.解析:当x ≤0时,f (x )=-x ,此时f (x )min =0; 当x >0时,f (x )=x 2-2x =(x -1)2-1, 此时f (x )min =-1.综上,当x ∈R 时,f (x )min =-1. 答案:-13.已知函数f (x )=x2m m 23-++ (m ∈Z)为偶函数,且f (3)<f (5),则m =________.解析:因为f (x )是偶函数, 所以-2m 2+m +3应为偶数. 又f (3)<f (5),即32m m 23-++<52m m 23-++,整理得⎝ ⎛⎭⎪⎫ 35 2m m 23-++<1,所以-2m 2+m +3>0,解得-1<m <32.又m ∈Z ,所以m =0或1.当m =0时,-2m 2+m +3=3为奇数(舍去); 当m =1时,-2m 2+m +3=2为偶数. 故m 的值为1.答案:14.已知直线y =-x +m 是曲线y =x 2-3ln x 的一条切线,则m 的值为________. 解析:因为直线y =-x +m 是曲线y =x 2-3ln x 的切线,所以令y ′=2x -3x=-1,得x =1或x =-32(舍),即切点为(1,1),又切点(1,1)在直线y =-x +m 上,所以m =2.答案:25.已知函数f (x )=⎩⎪⎨⎪⎧log 2x ,x ≥1,x +c ,x <1,则“c =-1”是“函数f (x )在R 上递增”的________条件(填“充要”“充分不必要”“必要不充分”“既不充分又不必要”).解析:若函数f (x )在R 上递增,则需log 21≥c +1,即c ≤-1.由于c =-1⇒c ≤-1,但c ≤-1⇒/ c =-1,所以“c =-1”是“f (x )在R 上递增”的充分不必要条件.答案:充分不必要6.设函数f (x )满足f (x )=1+f ⎝ ⎛⎭⎪⎫ 12 ·log 2x ,则f (2)=________. 解析:由已知得f ⎝ ⎛⎭⎪⎫ 12 =1-f ⎝ ⎛⎭⎪⎫ 12 ·log 22, 则f ⎝ ⎛⎭⎪⎫ 12 =12,则f (x )=1+12log 2x ,故f (2)=1+12log 22=32.答案:327.(2016·南京调研)设函数f (x )=x |x -a |,若对∀x 1,x 2∈[3,+∞),x 1≠x 2,不等式f x 1-f x 2x 1-x 2>0恒成立,则实数a 的取值范围是________.解析:由题意分析可知条件等价于f (x )在[3,+∞)上单调递增,又∵f (x )=x |x -a |,∴当a ≤0时,结论显然成立,当a >0时,f (x )=⎩⎪⎨⎪⎧x 2-ax ,x ≥a ,-x 2+ax ,x <a ,∴f (x )在⎝⎛⎭⎪⎫-∞,a 2上单调递增,在⎝ ⎛⎭⎪⎫a2,a 上单调递减,在(a ,+∞)上单调递增,∴0<a ≤3.综上,实数a 的取值范围是(-∞,3].答案:(-∞,3]8.设函数f (x )=e x(2x -1)-ax +a ,其中a <1,若存在唯一的整数x 使得f (x )<0,则a 的取值范围是________.解析:∵f (0)=-1+a <0,∴x =0.又∵x =0是唯一使f (x )<0的整数,∴⎩⎪⎨⎪⎧f -,f,即⎩⎪⎨⎪⎧e-1--1]+a +a ≥0,--a +a ≥0,解得a ≥32e .又∵a <1,∴32e ≤a <1.答案:⎣⎢⎡⎭⎪⎫32e ,19.在命题p 的四种形式(原命题、逆命题、否命题、逆否命题)中,真命题的个数记为f (p ),已知命题p :“若两条直线l 1:a 1x +b 1y +c 1=0,l 2:a 2x +b 2y +c 2=0平行,则a 1b 2-a 2b 1=0”.那么f (p )=________.解析:原命题p 显然是真命题,故其逆否命题也是真命题.而其逆命题是:若a 1b 2-a 2b 1=0,则两条直线l 1与l 2平行,这是假命题,因为当a 1b 2-a 2b 1=0时,还有可能l 1与l 2重合,逆命题是假命题,从而否命题也为假命题,故f (p )=2.答案:210.设函数f (x )=|2x-1|的定义域和值域都是[a ,b ](b >a ),则f (a )+f (b )=________. 解析:因为f (x )=|2x-1|的值域为[a ,b ],所以b >a ≥0,而函数f (x )=|2x-1|在[0,+∞)上是单调递增函数,因此应有⎩⎪⎨⎪⎧2a-1=a ,2b-1=b ,解得⎩⎪⎨⎪⎧a =0,b =1,所以有f (a )+f (b )=a+b =1.答案:111.已知函数f (x )=-2x1+|x |,若对区间M =[m ,n ],集合N ={}y | y =f x ,x ∈M ,且M =N ,则m -n =________.解析:显然函数f (x )=-2x1+|x |是奇函数,且在R 上是减函数,令f (x )=-x ,解得x=±1,所以m =-1,n =1,所以m -n =-2.答案:-212.已知函数f (x )的定义域为[-1,5],部分对应值如下表:f (x )的导函数y =f ′(x )的图象如图所示.下列关于函数f (x )的命题: ①函数f (x )的值域为[1,2]; ②函数f (x )在[0,2]上是减函数;③如果当x ∈[-1,t ]时,f (x )的最大值是2,那么t 的最大值为4; ④当1<a <2时,函数y =f (x )-a 最多有4个零点. 其中真命题的序号是________. 解析:由导数图象可知,当-1<x <0或2<x <4时,f ′(x )>0,函数单调递增, 当0<x <2或4<x <5时,f ′(x )<0,函数单调递减, 当x =0和x =4时,函数取得极大值f (0)=2,f (4)=2, 当x =2时,函数取得极小值f (2)=1.5. 又f (-1)=f (5)=1,所以函数的最大值为2,最小值为1,值域为[1,2],①正确.②正确. 因为当x =0和x =4时,函数取得极大值f (0)=2,f (4)=2,要使当x ∈[-1,t ]时函数f (x )的最大值是2, 则t 的最大值为5,所以③不正确. 由f (x )=a ,因为极小值f (2)=1.5,极大值为f (0)=f (4)=2, 所以当1<a <2时,y =f (x )-a 最多有4个零点, 所以④正确.故真命题的序号为①②④. 答案:①②④Ⅱ.大题规范练(限时45分钟) 解答题(本大题共4小题,共60分)13.(本小题满分14分)已知集合A =yy =x 2-32x +1,x ∈34,2,B ={}x | x +m 2≥1.若“x ∈A ”是“x ∈B ”的充分条件,求实数m 的取值范围.解:y =x 2-32x +1=⎝ ⎛⎭⎪⎫x -342+716,因为x ∈⎣⎢⎡⎦⎥⎤34,2,所以716≤y ≤2, 所以A =⎩⎪⎨⎪⎧⎭⎪⎬⎪⎫y ⎪⎪⎪716≤y ≤2. 由x +m 2≥1,得x ≥1-m 2, 所以B ={}x | x ≥1-m 2.因为“x ∈A ”是“x ∈B ”的充分条件, 所以A ⊆B ,所以1-m 2≤716,解得m ≥34或m ≤-34,故实数m 的取值范围是⎝ ⎛⎦⎥⎤-∞,-34∪⎣⎢⎡⎭⎪⎫34,+∞.14.(本小题满分14分)设f (x ) =a (x -5)2+6ln x ,其中a ∈R ,曲线y =f (x )在点(1,f (1))处的切线与y 轴相交于点(0,6).(1)确定a 的值;(2)求函数f (x )的单调区间与极值. 解:(1)因为f (x )=a (x -5)2+6ln x (x >0), 故f ′(x )=2a (x -5)+6x.令x =1,得f (1)=16a ,f ′(1)=6-8a , 所以曲线y =f (x )在点(1,f (1))处的切线方程为y -16a =(6-8a )·(x -1),由点(0,6)在切线上可得6-16a =8a -6, 故a =12.(2)由(1)知,f (x )=12(x -5)2+6ln x (x >0),f ′(x )=x -5+6x=x -x -x.令f ′(x )=0,解得x =2或x =3. 当0<x <2或x >3时,f ′(x )>0,故f (x )在(0,2),(3,+∞)上为增函数; 当2<x <3时,f ′(x )<0, 故f (x )在(2,3)上为减函数.由此可知f (x )在x =2处取得极大值f (2)=92+6ln 2,在x =3处取得极小值f (3)=2+6ln 3.15.(本小题满分16分)已知函数f (x )=k ·a -x(k ,a 为常数,a >0且a ≠1)的图象过点A (0,1),B (3,8).(1)求实数k ,a 的值; (2)若函数g (x )=f x -1f x +1,试判断函数g (x )的奇偶性,并说明理由.解:(1)把A (0,1),B (3,8)的坐标代入f (x )=k ·a -x,得⎩⎪⎨⎪⎧k ·a 0=1,k ·a -3=8.解得k =1,a =12.(2)g (x )是奇函数.理由如下: 由(1)知f (x )=2x,所以g (x )=f x -1f x +1=2x -12x +1.函数g (x )的定义域为R , 又g (-x )=2-x-12-x +1=2x ·2-x -2x2x ·2-x +2x=-2x-12x +1=-g (x ),所以函数g (x )为奇函数.16.(本小题满分16分)已知函数f (x )=x ln x ,g (x )=(-x 2+ax -3)e x(a 为实数). (1)当a =5时,求函数y =g (x )在x =1处的切线方程; (2)求f (x )在区间[t ,t +2](t >0)上的最小值. 解:(1)当a =5时,g (x )=(-x 2+5x -3)e x,g (1)=e. 又g ′(x )=(-x 2+3x +2)e x, 故切线的斜率为g ′(1)=4e.所以切线方程为:y -e =4e(x -1),即y =4e x -3e. (2)函数f (x )的定义域为(0,+∞),f ′(x )=ln x +1, 当x 变化时,f ′(x ),f (x )的变化情况如下表:①当t ≥1e 时,在区间[t ,t +2]上f (x )为增函数,所以f (x )min =f (t )=t ln t .②当0<t <1e 时,在区间⎣⎢⎡⎭⎪⎫t ,1e 上f (x )为减函数,在区间⎝ ⎛⎦⎥⎤1e ,t +2上f (x )为增函数, 所以f (x )min =f ⎝ ⎛⎭⎪⎫1e =-1e .。
2017物理提优综合六1、在一个很长的光滑平板车上,有两个物体1m 和2m (已知12m m ),如图1所示。
它们随着车一道做匀速直线运动,若车受到阻力而停止运动,则下列哪种情形可能发生:( )A. 1m 和2m 间距离缩小B. 1m 和2m 间距离增大C. 1m 和2m 间距离不变D. 条件不足,无法判断 图1 2、一只蜜蜂和一辆汽车在平直公路上以同样大小速度并列运动。
如果这只蜜蜂眼睛盯着汽车车轮边缘上某一点,那么它看到的这一点的运动轨迹是( )3、小明有“110V ,25W ”和“110V ,60W ”的灯泡各一只,可是家用的电源电压是220V 。
采用如下图所示的连接方式接入220V 的电源上,能使两灯均能正常发光的最佳方案是( )4、甲、乙两个实心均匀正方体物块放在水平地面上,它们的质量相等,密度关系是ρ甲>ρ乙,当在甲、乙两物块上,分别放重为G 1、G 2的物体或分别施加竖直向上的力F 1、F 2(F 1、F 2均小于物块重力)时,甲、乙两物块对水平地面的力的判断,下列说法正确的是( )A 、图甲的方法比较省力B 、图乙的方法比较省力C 、图甲和图乙两种方法所用的力大小相等D 、无法判断6、用水平推力F 将A 、B 两木块挤压在竖直墙壁图4上,木块B 受到墙壁的摩擦力为f 1,木块B 受到木块A 的摩擦力为f 2,木块B重为G B ,下列说法正确的是;( ) A 、f 1和f 2方向都是竖直向上 B 、f 1和f 2方向都是竖直向下 C 、f 1=G B +f 2 D 、f 1=G B ﹣f 27、用不等臂天平称质量为4g 的药品,先放在左盘中称,再放在右盘中称,记波段;人体的温度约为37℃,所辐射的电磁波中辐射强度最大的在红外波段。
宇宙空间内的电磁辐射相当于零下270℃的物体发出的,这种辐射称为“3K 背景辐射”。
“3K 背景辐射”的波段为( )A .γ射线B .x 射线C .紫外线D .无线电波9、一质量为M 的探空气球在匀速下降,若气球所受浮力F 始终保持不变,气球在运动过程中所受阻力大小仅与速度大小有关。
衡水中学2017届高三数学上学期六调试题(文带答案)2016-2017学年度上学期高三年级六调考试文数试卷第Ⅰ卷一、选择题:本大题共12个小题,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.1.已知集合,则()A.B.C.D.2.已知复数,则()A.B.C.D.3.为了得到函数的图象,只需把函数的图象()A.向左平移个单位长度B.向右平移个单位长度C.向左平移个单位长度D.向右平移个单位长度4.双曲线的离心率为()A.3B.2C.D.5.下表是降耗技术改造后生产甲产品过程中记录的产量(吨)与相应的生产能耗(吨标准煤)的几组对应数据,根据表中提供的数据,求出关于的线性回归方程为,则表中的值为()34562.544.5A.4B.3C.3.5D.4.56.执行如图所示的程序框图,则输出的结果为()A.B.C.-1D.27.已知函数,则其导函数的图象大致是()A.B.C.D.8.设直线与纵轴有直线所围成的封闭图形为区域,不等式组所确定的区域为,在区域内随机取一点,该点恰好在区域的概率为()A.B.C.D.以上答案均不正确9.如图,网格纸上小正方形的边长为1,粗实线画出的是某多面体的三视图,则该多面体最长的棱长等于()A.B.C.D.10.将函数的图象向右平移个单位长度后得到函数的图象,若的图象都经过点,则的值不可能是()A.B.C.D.11.已知是圆(为圆心)上一动点,线段的垂直平分线交于,则动点的轨迹方程为()A.B.C.D.12.已知函数,若对任意的,都有成立,则实数的取值范围是()A.B.C.D.第Ⅱ卷二、填空题:本题共4小题,每小题5分,满分20分,将答案填在答题纸上13.一个直六棱柱的底面是边长为2的正六边形,侧棱长为3,则它的外接球的表面积为.14.已知实数满足,则目标函数的最小值为.15.若向量夹角为,且,则与的夹角为.16.已知实数满足,实数满足,则的最小值为.三、解答题:解答应写出文字说明、证明过程或演算步骤.17.已知等差数列的前项和为,且成等比数列.(1)求数列的通项公式;(2)若数列的公差不为0,数列满足,求数列的前项和.18.某中学一位高三班主任对本班50名学生学习积极性和对待班级工作的态度进行调查,得到的统计数据如下表所示:积极参加班级工作不积极参加班级工作合计学习积极性高18725学习积极性不高61925合计242650(1)如果随机调查这个班的一名学生,那么抽到不积极参加班级工作且学习积极性不高的学生的概率是多少?(2)若不积极参加班级工作且学习积极性高的7名学生中有两名男生,现从中抽取两名学生参加某项活动,问两名学生中有1名男生的概率是多少?(3)学生的学习积极性与对待班极工作的态度是否有关系?请说明理由.附:0.100.050.0250.0100.0050.0012.7063.8415.0246.6357.87910.82819.如图,在四棱锥中,平面,底面是菱形,为与的交点,为棱上一点.(1)证明:平面平面;(2)若平面,求三棱锥的体积.20.已知抛物线的焦点为,抛物线上存在一点到焦点的距离为3,且点在圆上.(1)求抛物线的方程;(2)已知椭圆的一个焦点与抛物线的焦点重合,且离心率为.直线交椭圆于两个不同的点,若原点在以线段为直径的圆的外部,求实数的取值范围.21.已知函数,其中均为实数,为自然对数的底数.(1)求函数的极值;(2)设,若对任意的恒成立,求实数的最小值.请考生在22、23两题中任选一题作答,如果多做,则按所做的第一题记分.22.选修4-4:坐标系与参数方程在直角坐标系中,曲线是过点,倾斜角为的直线,以直角坐标系的原点为极点,轴正半轴为极轴建立极坐标系,曲线的极坐标方程是.(1)求曲线的普通方程和曲线的一个参数方程;(2)曲线与曲线相交于两点,求的值.23.选修4-5:不等式选讲设函数.(1)解不等式;(2)若存在,使不等式成立,求实数的取值范围.试卷答案一、选择题1-5:ACDBB6-10:DCBBD11、12:DA二、填空题13.14.-215.16.1三、解答题17.解:(1)由题得,,设等差数列的公差为,则,化简,得或.当时,,得,∴,即;当时,由,得,即;(2)由题意可知,,∴,①,②①-②,得,∴.18.解:(1)由题知,不积极参加班级工作且学习积极性不高的学生有19人,总人数为50人,所以;(2)设这7名学生分别为(大写为男生),则从中抽取两名学生的情况有:,,共21种情况,其中有1名男生的有10种情况,∴.(3)由题意得,,故有99.9%的把握认为“学生的学习积极性与对待班级工作的态度”有关系.19.解:(1)∵平面平面,∴.∵四边形是菱形,∴.又∵,∴平面.而平面,∴平面平面;(2)连接,∵平面,平面平面,∴.∵是的中点,∴是的中点.取的中点,连接,∵四边形是菱形,,∴,又,∴平面,且,故.20.解:(1)设点的坐标为.由题可知,,解得,∴抛物线的方程为;(2)由(1)得,抛物线的焦点,∵椭圆的一个焦点与抛物线的焦点重合,∴椭圆的半焦距,即,又椭圆的离心率为,∴,即,∴椭圆的方程为,设,由,得,由韦达定理,得,由,得,解得或,①∵原点在以线段的圆的外部,则,∴,即,②由①,②得,实数的范围是或,即实数的取值范围是.21.解:(1)由题得,,令,得.,列表如下:1大于00小于0极大值∴当时,取得极大值,无极小值;(2)当时,,∵在区间上恒成立,∴在区间上为增函数,设,∵在区间上恒成立,∴在区间上为增函数,不妨设,则等价于,即,设,则在区间上为减函数,∴在区间上恒成立,∴在区间上恒成立,∴,设,∵,∴,则在区间上为减函数,∴在区间上的最大值,∴,∴实数的最小值为.22.解:(1)∵,∴,即曲线的普通方程为,由题得,曲线的一个参数方程为(为参数);(2)设,把,代入中,得,整理得,,∴,∴.23.解:(1)由题得,,则有或或,解得或或,综上所述,不等式的解集为;(2)存在,使不等式成立等价于,由(1)知,时,,∴时,,故,即∴实数的取值范围为.。
2017届高三强化班提优练习六
1.已知sin(α+π3)+sin α=-435,-π2<α<0,则cos(α+2π3
)=________. 2.(2015全国)设α∈(0,π2),β∈(0,π2),且tan α=1+sin βcos β
,则2α-β=________. 3.△ABC 的三个内角A ,B ,C 所对的边分别为a ,b ,c ,a sin A sin B +b cos 2A =2a ,则b a
=________.
4.(2015·江西)在△ABC 中,内角A ,B ,C 所对的边分别是a ,b ,c .若c 2=(a -b )2+6,C =π3
,则△ABC 的面积是________.
5.已知α∈R ,sin α+2cos α=102
,则tan 2α=________. 6.(2014·江苏)若△ABC 的内角满足sin A +2sin B =2sin C ,则cos C 的最小值是________.
7.在△ABC 中,已知tan
A +
B 2=sin
C ,给出以下四个结论: ①tan A tan B
=1;②1<sin A +sin B ≤2;③sin 2A +cos 2B =1;④cos 2A +cos 2B =sin 2C . 其中一定正确的是________.
8.为了得到函数y =sin 3x +cos 3x 的图象,可以将函数y =2cos 3x 的图象向________平移________个单位.
9.已知α∈(π2,π),sin(α+π4)=35
,则cos α=________. 10.在△ABC 中,若sin C sin A =3,b 2-a 2=52
ac ,则cos B 的值为________. 11.设△ABC 的内角A ,B ,C 所对的边分别为a ,b ,c ,若b cos C +c cos B =a sin A ,则△ABC 的形状为________.
12.已知tan β=43,sin(α+β)=513
,其中α,β∈(0,π),则sin α的值为________. 13.已知△ABC 中,角A 、B 、C 的对边分别是a 、b 、c ,且tan B =2-3a 2-b 2+c
2,BC →·BA →=12,则tan B 等于________.
14.已知tan ⎝⎛⎭⎫α+π4=12,且-π2<α<0,则2sin 2α+sin 2αcos ⎝⎛⎭
⎫α-π4=________. 15.在△ABC 中,内角A 、B 、C 的对边长分别为a 、b 、c ,已知a 2-c 2=2b ,且sin A cos C =3cos A sin C ,则b =________.
16.已知0<α<π2<β<π,cos(β-π4)=13,sin(α+β)=45,则cos(α+π4)=________.
17.如图,嵩山上原有一条笔直的山路BC ,现在又新架设了一条索道AC ,小李在山脚B 处看索道AC ,发现张角∠ABC 为120°;从B 处攀登400米到达D 处,回头看索道AC ,发现张角∠ADC 为150°;从D 处再攀登800米方到达C 处,则索道AC 的长为________米.
18.设函数f (x )=cos(2x +π3
)+sin 2x . (1)求函数f (x )的最小正周期和最大值;
(2)若θ是第二象限角,且f (θ2)=0,求cos 2θ1+cos 2θ-sin 2θ
的值. 19.在△ABC 中,角A ,B ,C 所对的边分别为a ,b ,c ,满足a =2sin A ,cos B cos C +2a c +b c
=0. (1)求边c 的大小;
(2)求△ABC 面积的最大值.
19.已知角A 、B 、C 是△ABC 的三个内角,若向量m =(1-cos(A +B ),cos A -B 2),n =(58
,cos A -B 2),且m ·n =98
. (1)求tan A tan B 的值;
(2)求ab sin C a 2
+b 2-c 2的最大值. 20.在△ABC 中,角A ,B ,C 所对的边分别为a ,b ,c ,q =(2a,1),p =(2b -c ,cos C ),且q ∥p .
(1)求sin A 的值;
(2)求三角函数式-2cos 2C 1+tan C
+1的取值范围.。