2017海淀区高三年级第一学期期末练习-理科定稿1.11
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海淀区高三年级第一学期期末练习英语2017.01本试卷共12页,共150分。
考试时间120分钟。
注意事项:1.考生务必将答案答在答题卡上,在试卷上作答无效。
2.答题前考生务必将答题卡上的姓名、准考证号用黑色字迹的签字笔填写。
3.答题卡上选择题必须用2B铅笔作答,将选中项涂满涂黑,黑度以盖住框内字母为准,修改时用橡皮擦除干净。
非选择题必须用黑色字迹的签字笔按照题号顺序在各题目的答题区域内作答,未在对应的答题区域内作答或超出答题区域作答的均不得分。
第一部分:听力理解(共三节,30分)第一节(共5小题;每小题 1.5分,共7.5分)听下面5段对话。
每段对话后有一道小题,从每题所给的A、B、C三个选项中选出最佳选项。
听完每段对话后,你将有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话你将听一遍。
1.Which of the following does the woman suggest?A. B. C.2. What kind of novels does the woman like most?A. Fantasies.B. Science fiction.C. Detective stories.3.When do high schools usually start?A. At 8:30AM.B. At 8:15AM.C. At 7:30AM.4. What does the man invite the woman to do?A. Plan a wedding.B. Watch a new movie.C. Go to a concert.5. Where does the conversation most probably take place?A. At a gas station.B. At a car wash.C. At a repair shop.第二节(共10小题;每小题 1.5分,共15分)听下面4段对话或独白。
北京市海淀区高三第一学期期末测试2017.1 第二部分:知识运用(共两节,45分)第一节单项填空(共15小题;每小题1分,共15分)21. Things don’t always go as planned, ______ I still stay positive.A. orB. asC. butD. for22. —What a drive! I’m tired out.—No wonder! You have been driving for such a long time ______ taking a break.A. byB. withoutC. throughD. in23. The 24 solar terms(二十四节气) a great effect on Chinese people’s lives for thousandsof years.A. have hadB. hadC. haveD. had had24. ______ as a volunteer teacher in Tibet for a year, Linda has become more experienced.A. To workB. WorkingC. Having workedD. Worked25. Yesterday I went back to my primary school, ______ my teachers and I recalled our good olddays.A. whichB. thatC. whenD. where26. Li Hua’s parents hold different opinions on whether they should have ______ child.A. anotherB. otherC. othersD. the other27. Social media, like WeChat, ______ the way of communication nowadays.A. are changingB. changeC. changedD. were changing28. In big cities, young people often go to cafés with friends.A. relaxedB. relaxC. to relaxD. relaxing29. I usually sleep with the window open ______ it is really cold.A. ifB. unlessC. now thatD. in case30. Beijing’s new international airport ______ into use in 2019, according to the spokesperson.A. was putB. will putC. has putD. will be put31. I had to catch my flight. That was ______ I left Tom’s party so early yesterday.A. whatB. howC. whyD. when32. Jenny was practicing her speech in the hall when she heard her name ______.A. callingB. calledC. to callD. having called33. If you want to be on the school football team, you ______ train harder.A. canB. wouldC. mightD. must34. A long road tests a horse’s strength and a long-term task ______ a man’s heart.A. provesB. will proveC. is provingD. has proved35. If there were no cellphones, life ______ quite different because we depend too much on them.A. will beB. would beC. isD. were第二节完形填空(共20小题;每小题1.5分,共30分)I was the fool at school, regarded as a special needs student. I was termed as such. Obviously, because I was not interested in school and did not care for my __36__.Over time, I started to believe in my stupidity. I __37__ the fact that I was in special needs classes and poured it out as anger and depression. But one activity __38__ this view of myself: chess.I started to play chess with my father after school simply because I wanted to __39__ him at something. My father was a __40__ man, fond of physics, writing, religion, …, almost every __41__. He was called a walking dictionary. So, winning in chess against my father would be a __42__ that I had intellectual power. On the small chessboard, I had a chance to __43__ my so-called inability.Game after game, I wanted to beat my father even more. I started to study chess books and play against a chess computer to __44__ my skills. One weekend, I finally checkmated(将杀) my father on a ferry ride, which made me feel __45__ .Two years later, I became the second board on my school chess team, with our top board being the best high school player in the state. But before the tournament season, our top player __46__ to come. There came my chance to play as top board against the best players in other states.I was determined to show who I had become: a(n) __47__ person able to win with calculation, logic and will. My most __48__ game came in the final round. Our team was facing a high school which only excellent students attended. It was __49__ a match between a special needs student and a smart soul. My opponent(对手) was playing well and kept __50__ while I kept defending to keep my king safe. He spent long trying to break down my defenses, but could not find the final push. I __51__ with more defensive moves, trying to make it as difficult for him as possible. With little__52__ left, he started to make rapid moves. __53__ he could make the final decision, he ran out of time. Honestly, as his clock flag fell, I jumped up out of my seat and kissed the floor out of excitement. Of course it was not the most sportsmen-like __54__, but I could not control my emotions.While holding my winner’s cup, I knew I was not __55__. The inferiority complex(自卑感) had melted away, and I realized that underneath our thoughts, each person is a genius.36. A. habits B. grades C. plans D. benefits37. A. noticed B. explained C. accepted D. ignored38. A. changed B. supported C. questioned D. showed39. A. please B. comfort C. beat D. disturb40. A. smart B. strict C. quiet D. strong41. A. method B. topic C. event D. field42. A. dream B. lesson C. theory D. sign43. A. prove B. expose C. overcome D. promote44. A. teach B. sharpen C. choose D. invent45. A. overjoyed B. disappointed C. puzzled D. interested46. A. promised B. managed C. happened D. failed47. A. brave B. lucky C. active D. intelligent48. A. terrible B. memorable C. dangerous D. popular49. A. normally B. possibly C. actually D. partly50. A. attacking B. smiling C. pausing D. escaping51. A. returned B. quit C. won D. exchanged52. A. patience B. time C. energy D. wisdom53. A. Once B. Until C. Before D. Unless54. A. spirit B. thought C. comment D. behavior55. A. proud B. stupid C. bright D. lazy第三部分:阅读理解(共两节,40分)第一节(共15小题;每小题2分,共30分)AMy doorbell rings. On the step, I find the elderly Chinese lady, small and slight, holding the hand of a little boy. In her other hand, she holds a paper carrier bag.I know this lady. It is not her first visit. She is the boy’s grandmother, and her daugh ter bought the house next door last October.Her daughter, Nicole, speaks fluent English. But she is now in Shanghai, and her parents are here with the little boy. Nicole has obviously told her mother that I am having heart surgery soon, so her mother has decided I need more nutrients. (56题)I know what is inside the bag—a thermos with hot soup and a stainless-steel container with rice, vegetables and either chicken, meat or shrimp, sometimes with a kind of pancake. This has become an almost-daily practice.(57题) Communication between us is somewhat affected by the fact that she doesn’t speak English and all I can say in Chinese is hello. Once, she brought an iPad as well as the food. She pointed to the screen, which displayed a message from her daughter telling me that her mother wanted to know if the food was all right and whether it was too salty. I am not used to iPads, so she indicated I should go with her to her house. Then, she handed the iPad to her husband and almost immediately I found myself looking at Nicole in Shanghai and discussing her mother’s cooking and salt intake. Instantly, tears welled in my eyes.“Your mother just can’t be bringing me meals like this all the time,” I insisted. “I can hardly do dishes in return.”“Oh, no, Lucy.” Nicole said. “Mum doesn’t like western food. Don’t worry about it; she has to cook for the three of them anyway, and she wants to do it.”The doorbell keeps ringing and there is the familiar brown paper carrier bag, handed smilingly to me.I am now working on some more Chinese words—it’s the least I can do after such a display of kindness.“Thank you” is, of course, the first one. Somehow, it seems inadequate. (58题)56. The elderly Chinese lady visits Lucy regularly because______.A. Lucy pays her to deliver foodB. Lucy likes cooking Chinese foodC. she cares about Lucy’s state of healthD. she wants to make friends with Lucy57. Nicole’s mum took an iPad to Lucy’s home for_________.A. displayingB. communicatingC. cookingD. chatting58. In this passage Lucy mainly expresses her ______.A. preference for the Chinese foodB. gratitude to the Chinese familyC. love of the advanced technologyD. affection for the Chinese languageBChinese Emoji (表情符号) Circles Globe (62题)“Funny”, a made-in-China emoji, seems to have recently moved beyond China. Now, it is more than an emoji, but a cultural expansion.●Reaching Global MarketsA series of “funny” emoji-based bolsters (抱枕) have attracted the attention of Japanese customers. Even if one bolster is more than three times as expensive as in China, it doesn’t kill their desires to buy it. One Japanese customer Miki said, “They are just so cute and I bought three bolsters at one time for my family. And every time I see them, my mood just brightens suddenly.” (59题)A Japanese netizen Kiro Kara said, “I think the emoji implies very complicated meanings. My dad will send it when he doesn’t agree with someone but he has to say someth ing and behave politely.”●Addition to Domestic Social MediaCompared with Japanese impressions of the “funny” emoji, Chinese netizens prefer to use the emoji to tease one another on social media.One commonly seen online comment is, “We strongly suggest st opping the usage of the emoji. Because every time other people send me the emoji, I feel very uncomfortable and consider myself as a fool.”Regarded as the most popular emoji, the “funny” emoji has received much attention since its release in 2013. In fact, the “funny” emoji is the updated version of its original one; “funny” has a smiley mouth, two eyebrows and a naughty look. All these characteristics present users a sense of satire (讽刺). (60题)●In Everyday Use AbroadIt’s not the first time the Chi nese emoji takes the world stage. Earlier this year, one emoji from the Chinese basketball celebrity Yao Ming has been spread through the Middle East region. In a city in southern Egypt, Yao’s smiling emoji has appeared frequently in local traffic signs to remind people the road ahead is one-way. Many locals do not know Yao Ming but are familiar with his emoji and nickname “Chinese Funny Face”.As a new online language, emojis have become a necessary part of people’s daily life, helping people express their views in a more vivid and precise way. (61题) Also, it can help foreigners learn about Chinese culture. But how to properly use “the fifth innovation in China” without hurtingothers and turn them into commercial advantages still needanswers.59. Why do the bolsters attract Miki’s attention?A. They are inexpensive.B. They helpreach an agreement.C. They help brighten the mood.D. They are helpful to express desire.60. According to the passage, which of the following is the lates t “funny” emoji?A. B. C. D.61. Emojis are so popular worldwide mainly because people use them to ______.A. express their views more vividlyB. present their sense of satire directlyC. imply very complicated meanings properlyD. tease one another on social media purposely62. The main purpose of the text is to ______.A. promote the emoji worldwideB. teach us how to use the emojiC. explain the meaning the emojiD. show us the popularity of the emojiCEvery year billions of pounds are spent on hair loss treatment. If we succeed in curing hair loss with 3D printed hair follicles(毛囊), it will be a huge revolution.L’Oreal, the cosmetics firm is partnering with a French bio-printing company called Poietis, which has developed a form of laser(激光) printing for cell-based objects. Poietis’ technique begins with the creation of a digital map that determines where living cells and other tissue components should be placed to create the desired biological structure. This involves how the cells are expected to grow over time. The file based on the digital map is then turned into instructions for the printing equipment, so that it can lay down tiny droplets made out of the cell-based "bio ink" one layer at a time. The printing process involves bouncing a pulsing laser off a mirror and through a lens, so that when it hits a ribbon(色带) containing the bio ink, a droplet of the matter falls into place. About 10,000 of these micro-droplets are created every second. (63题)It typically takes about 10 minutes to print a piece of skin 1cm wide by 0.5mm thick. However, since hair follicles are complex and consist of 15 different cells in a structure, they may take longer.Poietis is not the only company working on bio-printing, but most others use another way, which involves pushing a bio-ink through a nozzle(喷嘴), rather than lasers to build their tissue.Poietis suggests its technique puts less stress on the biological matter, meaning there is less risk of causing it damage. (64题)Alopecia UK—a charity that provides support and advice about hair loss—has mixed feelings about the development. “It is encouraging to know that (66题)companies such as L’Oreal are investing in technology that may help those with hair loss in the future,” s aid spokeswoman Amy Johnson.(66题) “However, we would suggest it’s still very early to be getting excited about what this potentially could mean for those with medical hair loss. At this point it is unclear as to whether this technology could benefit those with all types of hair loss.” (65题)“Also, if this new technology does lead to a treatment option, given the high costs of existing hair transplant procedures, how many people will be able to realistically afford any new technological advances that may become available? (65题) As with any other research and development into processes that may be able to help those with hair loss, we watch with great interest.”63. What does Paragraph 2 mainly tell us?A. How the printing process is carried out.B. Where the living cells should be placed.C. How long the cells are expected to grow.D. What the printing equipment is made up of.64. What does the underlined word “it” in Paragraph 4 refer to?A. hair follicleB. biological matterC. nozzleD. bio-ink65. The passage implies that the new technology may ______.A. meet some practical challengesB. help people with hair loss at presentC. offer solutions to all problems of hair lossD. cost a large sum of money to transplant hair66. What is Amy Joh nson’s attitude towards the new technology?A. Disapproving.B. Optimistic.C. Cautious.D. Negative.DThere is no doubt eCommerce is growing, and it will continue to grow. However, physical stores would not die as a result of the rise of eCommerce, at least not in the near future. The idea that eCommerce is taking over physical stores has already misguided many people. Physical stores are far from vanishing, and there are some solid reasons for it. (69题)The projections for online spending is optimistic with $150 billion expected to be spent in the coming three years, yet we are also expecting (67题) $300 billion in spending at physical stores in the same duration. Do you still think that physical-store shopping is too small to sustain the eCommerce blow?Even though consumers are staying away from physical stores that follow older concepts, yet we are seeing the rise of fresh concept stores all around the US. We are seeing innovative and attractive success stories of physical stores, ranging from clothes stores to restaurants to health spas. It would be easy to assume that this trend will continue.Indeed, many shopping malls are dying, yet there are still those shopping centers that areperforming well. You can see this for yourself by visiting shopping malls near you. What I want to emphasize here is that not all shopping centers are made equal, just like not all eCommerce retailers are made equal. Both shopping malls and eCommerce sites can lose business if they fail to maintain productivity through improvements and innovations. (68题) When you visit shopping centers that are serious about their business, you would see their shops and parking lots packed.On the other hand, even e-tailers like Amazon have experimented with pop-up shopping concepts. It is important to bear in mind that consumers prefer face-to-face interactions instead of online interactions during shopping, meaning that physical stores are going to stay there.Still, eCommerce retailers are seeing all of their excitement disappear as they settle the sales tax problem associated with e-tailing. As of now, five states of America have already imposed sales tax on purchases through eCommerce sites, and e-tailers in those states have already witnessed 6 to 12 percent decrease in sales.This reinforces the fact that physical stores are here to stay, and if you are still undervaluing their growth, you are omitting a huge chunk of the retail representation. (69题)67. The underlined word "projections" in Paragraph 2 probably means____.A. intentionsB. assessmentsC. performancesD. predictions68. What can we infer from the passage?A. E-tailers are more creative businesses.B. Fresh concepts help build good business.C. Fewer consumers will visit physical stores.D. Physical stores can’t stand the blow of eCommerce.69. What is the best title for this passage?A. Is Offline Spending Greater Than Online Spending?B. Online Stores V.S. Physical Stores—What’s the Difference?C. Will Physical Stores replace eCommerce in the Near Future?D. Does eCommerce Success Mean Physical Stores Will Disappear?70. Which of the following shows the development of the passage?第二节(共5小题;每小题2分,共10分)根据短文内容,从短文后的七个选项中选出能填入空白处的最佳选项。
北京市海淀区高三年级第一学期期末练习数学(理科)一、选择题:本大题共8小题,每小题5分,共40分.在每小题列出的四个选项中,选出符合题目要求的一项.(1)已知全集U ,A B ⊆,那么下列结论中可能不成立的是( )(A )AB A = (B )A B B =(C )()U A B ≠∅ð (D )()U B A =∅ð(2)抛物线22y x =的准线方程为( ) (A )18y =-(B )14y =- (C )12y =- (D )1y =- (3)将函数cos 2y x =的图象按向量(,1)4a π=平移后得到函数()f x 的图象,那么( )(A )()sin 21f x x =-+ (B )()sin 21f x x =+ (C )()sin 21f x x =-- (D )()sin 21f x x =- (4)在ABC ∆中,角A 、B 、C 所对的边分别为a 、b 、c ,如果a c 3=,30B =?,那么角C 等于( )(A )120° (B )105° (C )90° (D )75° (5)位于北纬x 度的A 、B 两地经度相差90︒,且A 、B 两地间的球面距离为3R π(R 为地球半径),那么x 等于( )(A )30 (B ) 45 (C ) 60 (D )75 (6)已知定义域为R 的函数()f x ,对任意的R x Î都有1(1)()22f x f x +=-+恒成立,且1()12f =,则(62)f 等于 ( ) (A )1 (B ) 62 (C ) 64 (D )83(7)已知{},1,2,3,4,5αβÎ,那么使得sin cos 0αβ?的数对(),αβ共有( )(A) 9个 (B) 11个 (C) 12个 (D) 13个(8)如果对于空间任意()2n n ³条直线总存在一个平面α,使得这n 条直线与平面α所成的角均相等,那么这样的n ( )(A )最大值为3 (B )最大值为4 (C )最大值为5 (D )不存在最大值 二、填空题:本大题共6小题,每小题5分,共30分.把答案填在题中横线上. (9)22462limnnn ++++= .(10)如果()1,10,1x f x x ì£ïï=íï>ïî,, 那么()2f f 轾=臌 ;不等式()1212f x -?的解集是 .(11)已知点1F 、2F 分别是双曲线的两个焦点, P 为该双曲线上一点,若12PF F ∆为等腰直角三角形,则该双曲线的离心率为_____________.(12)若实数x 、y 满足20,,,x y y x y x b -≥⎧⎪≥⎨⎪≥-+⎩且2z x y =+的最小值为3,则实数b 的值为 .(13)已知直线0=++m y x 与圆222x y +=交于不同的两点A 、B ,O 是坐标原点,||||OA OB AB +?,那么实数m 的取值范围是 .(14)已知:对于给定的*q N Î及映射*:,N f AB B.若集合C A Í,且C 中所有元素对应的象之和大于或等于q ,则称C 为集合A 的好子集. ① 对于2q =,{},,A a b c =,映射:1,f x x A ,那么集合A 的所有好子集的个数为 ;② 对于给定的q ,{}1,2,3,4,5,6,A π=,映射:f A B ®的对应关系如下表:x12 3 4 5 6π()f x1 1 1 1 1yz若当且仅当C 中含有π和至少A 中2个整数或者C 中至少含有A 中5个整数时,C 为集合A 的好子集.写出所有满足条件的数组(),,q y z : . 三、解答题: 本大题共6小题,共80分.解答应写出文字说明, 演算步骤或证明过程. (15)(本小题共12分)已知函数22()sin )cos()cos 44f x x x x x ππ=++---. (Ⅰ)求函数)(x f 的最小正周期和单调递减区间;(Ⅱ)求函数)(x f 在25,1236ππ轾犏-犏臌上的最大值和最小值并指出此时相应的x 的值. (16)(本小题共12分)已知函数)(x g 是2()(0)f x x x =>的反函数,点),(00y x M 、),(00x y N 分别是)(x f 、)(x g 图象上的点,1l 、2l 分别是函数)(x f 、)(x g 的图象在N M ,两点处的切线,且1l ∥2l . (Ⅰ)求M 、N 两点的坐标;(Ⅱ)求经过原点O 及M 、N 的圆的方程. (17)(本小题共14分)已知正三棱柱111C B A ABC -中,点D 是棱AB的中点,11,BC AA ==.(Ⅰ)求证://1BC 平面DC A 1; (Ⅱ)求1C 到平面1A DC 的距离; (Ⅲ)求二面角1D AC A --的大小.(18)(本小题共14分)某种家用电器每台的销售利润与该电器的无故障使用时间T (单位:年)有关. 若1≤T ,则销售利润为0元;若31≤<T ,则销售利润为100元;若3>T ,则销售利润为200元. 设每台该种电器的无故障使用时间1≤T ,31≤<T 及3>T 这三种情况发生的概率分别为321,,p p p ,又知21,p p 是方程015252=+-a x x 的两个根,且32p p =.(Ⅰ)求321,,p p p 的值;(Ⅱ)记ξ表示销售两台这种家用电器的销售利润总和,求ξ的分布列; (Ⅲ)求销售两台这种家用电器的销售利润总和的平均值. (19)(本小题共14分)已知点()0,1A 、()0,1B -,P 是一个动点,且直线PA 、PB 的斜率之积为12-. (Ⅰ)求动点P 的轨迹C 的方程;(Ⅱ)设()2,0Q ,过点()1,0-的直线l 交C 于M 、N 两点,QMN ∆的面积记为S ,若对满足条件的任意直线l ,不等式tan S MQN λ≤恒成立,求λ的最小值. (20)(本小题共14分)如果正数数列{}n a 满足:对任意的正数M ,都存在正整数0n ,使得0n a M >,则称数列{}n a 是一个无界正数列.(Ⅰ)若()32s i n ()1,2,3,n a n n =+=, 1, 1,3,5,,1, 2,4,6,,2n n nb n n ⎧=⎪⎪=⎨+⎪=⎪⎩分别判断数列{}n a 、{}n b 是D C 1B 1A 1CBA否为无界正数列,并说明理由;(Ⅱ)若2n a n =+,是否存在正整数k ,使得对于一切n k ≥,有1223112n n a a a n a a a ++++<-成立; (Ⅲ)若数列{}n a 是单调递增的无界正数列,求证:存在正整数m ,使得122312009mm m a a a a a a +-+++<. 海淀区高三年级第一学期期末练习 数学(理科)参考答案及评分标准 2009.01一、选择题(本大题共8小题,每小题5分,共40分)CABAB DDA二、填空题(本大题共6小题,每小题5分.有两空的小题,第一空3分,第二空2分,共30分) (9)1 (10)1,[0,1] (111(12)94(13)(2,[2,2)- (14) 4,(5,1,3) 三、解答题(本大题共6小题,共80分) (15)(本小题共12分)解:(Ⅰ)22()sin )cos()cos 44f x x x x x ππ=++-- 2sin(2)6x π=- ………………………………………………4分所以22T ππ==. ………………………………………………5分 由()3222262Z k x k k πππππ+???得所以函数)(x f 的最小正周期为π,单调递减区间为5[,]36k k ππππ++()k ∈Z .………………………………………………7分 (Ⅱ)由(Ⅰ)有()2sin(2)6f x x π=-.因为25,1236x ππ轾犏?犏臌, 所以112,639x πππ轾犏-?犏臌. 因为411sin()sin sin 339πππ-=<,所以当12x π=-时,函数)(x f取得最小值-3x π=时,函数)(x f 取得最大值2.………………………………………………12分(16)(本小题共12分) 解:(Ⅰ)因为2()(0)f x x x =>,所以()0)g x x =>.从而,2)(x x f ='()g x ¢=. ………………………………………………3分所以切线21,l l 的斜率分别为,2)(001x x f k ='=00221)(y y g k ='=.又2000(0)y x x =>,所以2012k x =. ………………………………………………4分 因为两切线21,l l 平行,所以21k k =. ………………………………………………5分从而20(2)1x =.因为00x >, 所以012x =. 所以N M ,两点的坐标分别为)21,41(),41,21(. ………………………………………7分 (Ⅱ)设过O 、M 、N 三点的圆的方程为:220x y Dx Ey F ++++=.因为圆过原点,所以0F =.因为M 、N 关于直线y x =对称,所以圆心在直线y x =上. 所以D E =.又因为11(,)24M 在圆上, 所以512D E ==-. 所以过O 、M 、N 三点的圆的方程为:225501212x y x y +--=. ………………12分 (17)(本小题共14分)(Ⅰ)证明:连结1AC 交1A C 于点G ,连结DG .在正三棱柱111C B A ABC -中,四边形11ACC A 是平行四边形, ∴DG ∥1BC . ………………………………………2分∵DG ⊂平面1A DC ,1BC ⊄平面1A DC ,∴1BC ∥平面1A DC .………………………………………4分解法一:(Ⅱ)连结1DC ,设1C 到平面1A DC 的距离为h .∵四边形11ACC A 是平行四边形,∴1118C A CD V -=. ………………………………………6分在等边三角形ABC 中,D 为AB 的中点, ∵AD 是1A D 在平面ABC 内的射影,∴1CD A D ^. ………………………………………8分∴111313C A DC A DCV h S -∆==. ………………………………………9分 (Ⅲ)过点D 作DE AC ⊥交AC 于E ,过点D 作1DF A C ⊥交1A C 于F ,连结EF .∵平面ABC ⊥平面11ACC A ,DE ⊂平面ABC ,平面ABC平面11ACC A AC =,∴DE ⊥平面11ACC A .∴EF 是DF 在平面11ACC A 内的射影.∴DFE Ð是二面角1D AC A --的平面角. ………………………………………12分 在直角三角形ADC中,AD DC DE AC ×==同理可求:118A D DC DF AC ×==.∴DFE ?………………………………………14分解法二:过点A 作AO BC ⊥交BC 于O ,过点O 作F ED C 1B 1A 1CBAOE BC ⊥交11B C 于E .因为平面ABC ⊥平面11CBB C ,所以AO ⊥平面11CBB C .分别以,,CB OE OA 所在的直线为x 轴,y 轴,z 轴建立空间直角坐标系,如图所示.因为11,BC AA ==,ABC ∆是等边三角形,所以O 为BC 的中点.则()0,0,0O ,A ⎛ ⎝⎭,1,0,02C ⎛⎫- ⎪⎝⎭,1A ⎛ ⎝⎭,1(4D ,112C ⎛⎫- ⎪⎝⎭. ………………………………………6分 (Ⅱ)设平面1A DC 的法向量为(),,n x y z =,则取x =1A DC 的一个法向量为()3,1,3n =-. ………………………………………8分∴1C 到平面1A DC 的距离为:13913CC n n⋅=………………………………………10分 (Ⅲ)解:同(Ⅱ)可求平面1ACA 的一个法向量为()13,0,1n =-. …………………………12分设二面角1D AC A --的大小为θ,则1cos cos ,n n θ=<>=∴θ=. ………………………………………14分 (18)(本小题共14分)解:(Ⅰ)由已知得1321=++p p p .21,p p 是方程015252=+-a x x 的两个根, ∴511=p ,5232==p p . ………………………………………3分 (Ⅱ)ξ的可能取值为0,100,200,300,400. ………………………………………4分()400=ξP =2545252=⨯. ………………………………………9分随机变量ξ的分布列为:ξ 0 100 200 300 400P251 254 258 258 254………………………………………11分 (Ⅲ)销售利润总和的平均值为E ξ=2544002583002582002541002510⨯+⨯+⨯+⨯+⨯=240. ∴销售两台这种家用电器的利润总和的平均值为240元.………………………………………14分注:只求出E ξ,没有说明平均值为240元,扣1分. (19)(本小题共14分)解:(Ⅰ)设动点P 的坐标为(),x y ,则直线,PA PB 的斜率分别是11,y y x x-+. 由条件得1112y y x x-+?-. 即()22102x y x +=?. 所以动点P 的轨迹C 的方程为()22102x y x +=?. ………………………………………5分 注:无0x ¹扣1分. (Ⅱ)设点,M N 的坐标分别是()()1122,,,x y x y .当直线l 垂直于x 轴时,21212111,,2x x y y y ==-=-=. 所以()()()1122112,,2,2,QM x y QN x y x y =-=-=--. 所以()22111722QM QNx y ?--=. ………………………………………7分 当直线l 不垂直于x 轴时,设直线l 的方程为()1y k x =+,由221,2(1)x y y k x ìïï+=ïíïï=+ïî得()2222124220k x k x k +++-=. 所以 2122, 21422212221k k x x k k x x +-=+-=+. ………………………………………9分 所以()()()12121212122224QM QNx x y y x x x x y y ?--+=-+++.因为()()11221,1y k x y k x =+=+, 所以()()()()2221212217131712422212QM QNk x x k x x k k ?++-+++=-<+.综上所述⋅的最大值是217. ………………………………………11分 因为tan S MQN λ≤恒成立,即1sin ||||sin 2cos MQN QM QN MQN MQNλ⋅≤恒成立. 由于()2171302212QM QNk ?->+. 所以cos 0MQN >.所以2QM QN λ⋅≤恒成立. ………………………………………13分 所以λ的最小值为174. ………………………………………14分 注:没有判断MQN Ð为锐角,扣1分. (20)(本小题共14分)解:(Ⅰ){}n a 不是无界正数列.理由如下:取M = 5,显然32sin()5n a n =+≤,不存在正整数0n 满足05n a >;{}n b 是无界正数列.理由如下:对任意的正数M ,取0n 为大于2M 的一个偶数,有0012122n n M b M ++=>>,所以{}n b 是无界正数列. ………………………………………4分(Ⅱ)存在满足题意的正整数k .理由如下: 当3n ³时, 因为12231n n a a a n a a a +⎛⎫-+++⎪⎝⎭32121231n nn a a a a a a a a a ++---=+++即取3k =,对于一切n k ≥,有1223112n n a a a n a a a ++++<-成立. ……………………9分 注:k 为大于或等于3的整数即可.(Ⅲ)证明:因为数列{}n a 是单调递增的正数列,所以12231n n a a a n a a a +⎛⎫-+++ ⎪⎝⎭32121231n nn a a a a a a a a a ++---=+++即12123111n n n a a a a n a a a a +++++<-+. 因为{}n a 是无界正数列,取12M a =,由定义知存在正整数1n ,使1112n a a +>. 所以1112123112n n a a a n a a a ++++<-.由定义可知{}n a 是无穷数列,考察数列11n a +,12n a +,13n a +,…,显然这仍是一个单调递增的无界正数列,同上理由可知存在正整数2n ,使得()112112122123112n n n n n n a a a n n a a a ++++++++<--.重复上述操作,直到确定相应的正整数4018n .则401840181212140184017231111222n n a a a n n n n n a a a +⎛⎫⎛⎫⎛⎫+++<-+--++-- ⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭即存在正整数4018m n =,使得122312009mm m a a a a a a +-+++<成立. ………………………………………14分。
2017年北京市海淀区高三理科上学期数学期末试卷一、选择题(共8小题;共40分)1. 已知i为虚数单位,则5i1−2i= A. 2+iB. −2+iC. 2−iD. −2−i2. 在极坐标系Ox中,方程ρ=2sinθ表示的圆为 A. B.C. D.3. 执行如图所示的程序框图,输出的k值为 A. 4B. 5C. 6D. 74. 设m是不为零的实数,则“m>0”是“方程x2m −y2m=1表示双曲线”的 A. 充分而不必要条件B. 必要而不充分条件C. 充分必要条件D. 既不充分也不必要条件5. 已知直线x−y+m=0与圆O:x2+y2=1相交于A,B两点,且△OAB为正三角形,则实数m的值为 A. 32B. 62C. 32或−32D. 62或−626. 从编号分别为1,2,3,4,5,6的六个大小完全相同的小球中,随机取出三个小球,则恰有两个小球编号相邻的概率为 A. 15B. 25C. 35D. 457. 某三棱锥的三视图如图所示,则下列说法中:①三棱锥的体积为16;②三棱锥的四个面全是直角三角形;③三棱锥四个面的面积中最大的值是32.所有正确的说法是 A. ①B. ①②C. ②③D. ①③8. 已知点F为抛物线C:y2=2px p>0的焦点,点K为点F关于原点的对称点,点M在抛物线C上,则下列说法错误的是 A. 使得△MFK为等腰三角形的点M有且仅有4个B. 使得△MFK为直角三角形的点M有且仅有4个C. 使得∠MKF=π4的点M有且仅有4个D. 使得∠MKF=π6的点M有且仅有4个二、填空题(共6小题;共30分)9. 点2,0到双曲线x24−y2=1的渐近线的距离是.10. 已知公差为1的等差数列a n中,a1,a2,a4成等比数列,则a n的前100项的和为.11. 设抛物线C:y2=4x的顶点为O,经过抛物线C的焦点且垂直于x轴的直线和抛物线C交于A,B两点,则OA+OB=.12. 已知5x−1n的展开式中,各项系数的和与各项二项式系数的和之比为64:1,则n=.13. 已知正方体ABCD−A1B1C1D1的棱长为4,M是棱BC的中点,点P在底面ABCD内,点Q在线段A1C1上.若PM=1,则PQ长度的最小值为.14. 对任意实数k,定义集合D k=x,y x−y+2≥0,x+y−2≤0,x,y∈R kx−y≤0.①若集合D k表示的平面区域是一个三角形,则实数k的取值范围是;②当k=0时,若对任意的x,y∈D0,有y≥a x+3−1恒成立,且存在x,y∈D0,使得x−y≤a成立,则实数a的取值范围为.三、解答题(共6小题;共78分)15. 如图,在△ABC中,点D在AC边上,且AD=3DC,AB=,∠ADB=π3,∠C=π6.(1)求DC的值;(2)求tan∠ABC的值.16. 据中国日报网报道:2017年11月13日,TOP500发布的最新一期全球超级计算机500强榜单显示,中国超算在前五名中占据两席.其中超算全球第一“神威·太湖之光”完全使用了国产处理器.为了了解国产品牌处理器打开文件的速度,某调查公司对两种国产品牌处理器进行了12次测试,结果如下:(数值越小,速度越快,单位是MIPS)测试1测试2测试3测试4测试5测试6测试7测试8测试9测试10测试11测试品牌A3691041121746614品牌B2854258155121021(1)从品牌A的12次测试结果中,随机抽取一次,求测试结果小于7的概率;(2)在12次测试中,随机抽取三次,记X为品牌A的测试结果大于品牌B的测试结果的次数,求X的分布列和数学期望E X;(3)经过了解,前6次测试是打开含有文字与表格的文件,后6次测试是打开含有文字与图片的文件.请你依据表中数据,运用所学的统计知识,对这两种国产品牌处理器打开文件的速度进行评价.17. 如图1,在梯形ABCD中,AD∥BC,CD⊥BC,BC=CD=1,AD=2,E为AD中点.将△ABE沿BE翻折到△A1BE的位置,使A1E=A1D如图2.(1)求证:平面A1ED⊥平面BCDE;(2)求A1B与平面A1CD所成角的正弦值;(3)设M,N分别为A1E和BC的中点,试比较三棱锥M−A1CD和三棱锥N−A1CD(图中未画出)的体积大小,并说明理由.18. 已知椭圆C:x2+2y2=9,点P2,0.(1)求椭圆C的短轴长与离心率;(2)过1,0的直线l与椭圆C相交于M,N两点,设MN的中点为T,判断TP与TM 的大小,并证明你的结论.19. 已知函数f x=2e x−ax2−2x−2.(1)求曲线y=f x在点0,f0处的切线方程;(2)当a≤0时,求证:函数f x有且只有一个零点;(3)当a>0时,写出函数f x的零点的个数.(只需写出结论)20. 无穷数列a n满足:a1为正整数,且对任意正整数n,a n+1为前n项a1,a2,⋯,a n中等于a n的项的个数.(1)若a1=2,请写出数列a n的前7项;(2)求证:对于任意正整数M,必存在k∈N∗,使得a k>M;(3)求证:“a1=1”是“存在m∈N∗,当n≥m时,恒有a n+2≥a n成立”的充要条件.答案第一部分 1. B 2. D 3. D 【解析】s =20+21+22+⋯+2k=1−2k +11−2=2k +1−1,当 k =5 时,26−1<100,当 k =6 时,27−1>100,则 k =k +1=7,输出 k =7.4. A5. D6. C7. D8. C第二部分9. 25 5 10. 5050 11. 2 12.6 13. 14. −1,1 , −2,15 第三部分15. (1) 由题意得,∠DBC=∠ADB −∠C =π3−π6=π6, 故 ∠DBC =∠C ,DB =DC , 设 DC =x ,则 DB =x ,DA =3x . 在 △ADB 中,由余弦定理得,AB 2=DA 2+DB 2−2DA ⋅DB ⋅cos ∠ADB , 即 7= 3x 2+x 2−2⋅3x ⋅x ⋅12=7x 2, 解得 x =1,即 DC =1.(2) 方法一.在 △ADB 中,由 AD >AB ,得 ∠ABD >∠ADB =60∘,故∠ABC =∠ABD +∠DBC>π3+π6=π2, 在 △ABC 中,由正弦定理得,AC sin ∠ABC =ABsin ∠ACB , 即 4sin ∠ABC =712,故 sin ∠ABC =7,由 ∠ABC ∈ π2,π ,得 cos ∠ABC = 37,tan ∠ABC = 3=−23 3.方法二.在 △ADB 中,由余弦定理得,cos ∠ABD =AB 2+BD 2−AD 2=2⋅ 7⋅1=2 7由 ∠ABD ∈ 0,π ,故 sin ∠ABD = 32 7,故 tan ∠ABD =−3 3, 故tan ∠ABC=tan ∠ABD +π=tan ∠ABD +tan π61−tan ∠ABD ⋅tanπ6=−3 3+33 3 33=−2 3.方法三:BC 2=BD 2+CD 2−2BD ⋅CD ⋅cos ∠BDC =3,BC = 3,cos ∠ABC =BA 2+BC 2−AC 22BA⋅BC= 3 7, 因为 ∠ABC ∈ 0,π , 所以 sin ∠ABC =7,所以 tan ∠ABC = 3=−23 3.16. (1) 从品牌A 的 12 次测试中,测试结果打开速度小于 7 的测试有:测试 1,2,5,6,9,10,11,共 7 次,设“该测试结果打开速度小于 7”为事件A ,因此 P A =712.(2) 12 次测试中,品牌A 的测试结果大于品牌B 的测试结果的测试有:测试 1,3,4,5,7,8,共 6 次,随机变量 X 所有可能的取值为:0,1,2,3, P X =0 =C 63C 6C 123=111, P X =1 =C 62C 61C 123=922, P X =2 =C 61C 62C 123=922,P X =3 =C 60C 63C 123=111,随机变量 X 的分布列为:X 0123P 1991E X =111×0+922×1+922×2+111×3=32.(3) 标准 1:会用前 6 次测试品牌A 、品牌B 的测试结果的平均值与后 6 次测试品牌A 、品牌B 的测试结果的平均值进行阐述(这两种品牌的处理器打开含有文字与表格的文件的测试结果的平均值均小于打开含有文字和图片的文件的测试结果的平均值;这两种品牌的处理器打开含有文字与表格的文件的平均速度均快于打开含有文字和图片的文件的平均速度).【解析】标准2:会用前6次测试品牌A、品牌B的测试结果的方差与后6次测试品牌A、品牌B的测试结果的方差进行阐述(这两种品牌的处理器打开含有文字与表格的文件的测试结果的方差均小于打开含有文字和图片的文件的测试结果的方差;这两种品牌的处理器打开含有文字与表格的文件的速度的波动均小于打开含有文字和图片的文件的速度的波动).标准3:会用品牌A前6次测试结果的平均值、后6次测试结果的平均值与品牌B前6次测试结果的平均值、后6次测试结果的平均值进行阐述(品牌A前6次测试结果的平均值大于品牌B前6次测试结果的平均值,品牌A后6次测试结果的平均值小于品牌B后6次测试结果的平均值,品牌A打开含有文字和表格的文件的速度慢于品牌B,品牌A,打开含有文字和图形的文件的速度快于品牌B).标准4:会用品牌A前6次测试结果的方差、后6次测试结果的方差与品牌B前6次测试结果的方差、后6次测试结果的方差进行阐述(品牌A前6次测试结果的方差大于品牌B前6次测试结果的方差,品牌A 后6次测试结果的方差小于品牌B后6次测试结果的方差,品牌A打开含有文字和表格的文件的速度的波动大于品牌B,品牌A,打开含有文字和图形的文件的速度的波动小于品牌B).标准5:会用品牌A这12次测试结果的平均值与品牌B这12次测试结果的平均值进行阐述(品牌A这12次测试结果的平均值小于品牌B这12次测试结果的平均值,品牌A打开文件的平均速度快于品牌B).标准6:会用品牌A这12次测试结果的方差与品牌B这12次测试结果的方差进行阐述(品牌A这12次测试结果的方差小于品牌B这12次测试结果的方差,品牌A打开文件的平均速度的波动小于品牌B).标准7:会用前6次测试中,品牌A测试结果大于(小于)品牌B测试结果的次数、后6次测试中,品牌A测试结果大于(小于)品牌B测试结果的次数进行阐述(前6次测试结果中,品牌A小于品牌B的有2次,占1/3,后6次测试中,品牌A小于品牌B的有4次,占2/3.故品牌A打开含有文字和表格的文件的速度慢于品牌B,品牌A打开含有文字和图片的文件的速度快于品牌B).标准8:会用这12次测试中,品牌A测试结果大于(小于)品牌B测试结果的次数进行阐述(这12次测试结果中,品牌A小于品牌B的有6次,占1/2.故品牌A和品牌B打开文件的速度相当).参考数据:期望前6次后6次12次品牌A 5.509.837.67品牌B 4.3311.838.08品牌A与品牌B 4.9210.83方差前6次后6次12次品牌A12.3027.3723.15品牌B 5.0731.7732.08品牌A与品牌B8.2727.9717. (1)由图1,在梯形ABCD中,AD∥BC,CD⊥BC,BC=1,AD=2,E为AD中点,BE⊥AD,故图2,BE⊥A1E,BE⊥DE,因为A1E∩DE=E,A1E,DE⊂平面A1DE,所以BE⊥平面A1DE,因为BE⊂平面BCDE,所以平面A1DE⊥平面BCDE.(2)解一:取DE中点O,连接OA1,ON.因为在△A1DE中,A1E=A1D=DE=1,O为DE中点,所以A1O⊥DE,因为平面A1DE⊥平面BCDE,平面A1DE∩平面BCDE=DE,A1O⊂平面A1DE,所以A1O⊥平面BCDE,因为在正方形BCDE中,O,N分别为DE,BC的中点,所以ON⊥DE,建系如图.则A10,0,32,B1,−12,0,C1,12,0,D0,12,0,E0,−12,0,A1B=1,−12,−32,A1D=0,12,−32,DC=1,0,0,设平面A1CD的法向量为n=x,y,z,则n⋅A1D=0,n⋅DC=0,即12y−32z=0,x=0,令z=1得,y=3,所以n=0,3,1是平面A1CD的一个法向量.cos A1B,n=A1B⋅nA1B⋅ n =32⋅2=−64,所以A1B与平面A1CD所成角的正弦值为64.解二:在平面A1DE内作Ez⊥ED.由BE⊥平面A1DE,建系如图.则A10,12,32,B1,0,0,C1,1,0,D0,1,0,E0,0,0.A1B=1,−12,−32,A1D=0,12,−32,DC=1,0,0,设平面A1CD的法向量为n=x,y,z,则n⋅A1D=0,n⋅DC=0,即12y−32z=0,x=0,令z=1得,y=3,所以n=0,3,1是平面A1CD的一个法向量.cos A1B,n=A1B⋅nA1B⋅ n =32⋅2=−64,所以A1B与平面A1CD所成角的正弦值为64.(3)三棱锥M−A1CD和三棱锥N−A1CD的体积相等.理由如下:方法一:连接MN,由M0,14,34,N1,12,0,知MN=1,14,−34,则MN⋅n=0,因为MN⊄平面A1CD,所以MN∥平面A1CD.故点M,N到平面A1CD的距离相等,有三棱锥M−A1CD和N−A1CD同底等高,所以体积相等.方法二:如图,取DE中点P,连接MP,NP,MN.因为在△A1DE中,M,P分别是A1E,DE的中点,所以MP∥A1D,因为在正方形BCDE中,N,P分别是BC,DE的中点,所以NP∥CD,因为MP∩NP=P,MP,NP⊂平面MNP,A1D,CD⊂平面A1CD,所以平面MNP∥平面A1CD,因为MN⊂平面MNP,所以MN∥平面A1CD,故点M,N到平面A1CD的距离相等,有三棱锥M−A1CD和N−A1CD同底等高,所以体积相等.方法三:如图,取A1D中点Q,连接MN,MQ,CQ.因为在△A1DE中,M,Q分别是A1E,A1D的中点,所以MQ∥ED且MQ=12ED,因为在正方形BCDE中,N是BC的中点,所以NC∥ED且NC=12ED,所以MQ∥NC且MQ=NC,故四边形MNCQ是平行四边形,故MN∥CQ,因为CQ⊂平面A1CD,MN⊄平面A1CD,所以MN∥平面A1CD.故点M,N到平面A1CD的距离相等,有三棱锥M−A1CD和N−A1CD同底等高,所以体积相等.18. (1)C:x29+y292=1,故a2=9,b2=92,c2=92,有a=3,b=c=322.椭圆C的短轴长为2b=3e=ca =22.(2)方法1:结论是:TP<TM.当直线l斜率不存在时,l:x=1,TP=0<TM=2,当直线l斜率存在时,设直线l:y=k x−1,M x1,y1,N x2,y2,x2+2y2=9,y=k x−1,整理得:2k2+1x2−4k2x+2k2−9=0,Δ=4k22−42k2+12k2−9=64k2+36>0,故x1+x2=4k22k2+1,x1x2=2k2−92k2+1,PM⋅PN=x1−2x2−2+y1y2=x1−2x2−2+k2x1−1x2−1=k2+1x1x2−k2+2x1+x2+k2+4=k2+1⋅2k2−92k2+1−k2+2⋅4k22k2+1+k2+4 =−6k2+52k2+1<0.故∠MPN>90∘,即点P在以MN为直径的圆内,故TP<TM.方法2:结论是:TP<TM.当直线l斜率不存在时,l:x=1,TP=0<TM=2,当直线l斜率存在时,设直线l:y=k x−1,M x1,y1,N x2,y2,T x T,y T,x2+2y2=9,y=k x−1,整理得:2k2+1x2−4k2x+2k2−9=0,Δ=4k22−42k2+12k2−9=64k2+36>0,故x1+x2=4k22k+1,x1x2=2k2−92k+1,x T=12x1+x2=2k22k2+1,y T=k x T−1=−k2k2+1,TP2=x T−22+y T2=2k22−22+ −k22=2k2+22+k22k2+12=4k4+9k2+42k2+12.TM2=12MN2=14k2+1x1−x22=14k2+1x1+x22−4x1x2=14k2+14k22k2+12−4⋅2k2−92k2+1=k2+116k2+9=16k4+25k2+92k2+12.此时,TM2− TP2=16k4+25k2+92k2+12−4k4+9k2+42k2+12=12k4+16k2+522>0.故TM>TP.19. (1)因为函数f x=2e x−ax2−2x−2,所以fʹx=2e x−2ax−2,故f0=0,fʹ0=0,则曲线y=f x在x=0处的切线方程为y=0.(2)当a≤0时,令g x=fʹx=2e x−2ax−2,则gʹx=2e x−2a>0,故g x是R上的增函数,由g0=0,故当x<0时,g x<0,当x>0时,g x>0,即当x<0时,fʹx<0,当x>0时,fʹx>0,故f x在−∞,0上单调递减,在0,+∞上单调递增,函数f x的最小值为f0.由f0=0,故f x有且仅有一个零点.(3)当0<a<1时,f x有两个零点,当a=1时,f x有一个零点;当a>1时,f x有两个零点.20. (1)若a1=2,则数列a n的前7项为2,1,1,2,2,3,1.(2)证法一:假设存在正整数M,使得对任意的k∈N∗,a k≤M,由题意,a k∈1,2,3,⋯,M,故数列a n至多有M个不同的取值,考虑数列a n的前M2+1项:a1,a2,a3,⋯,a M2+1,其中至少有M+1项的取值相同,不妨设a i1=a i2=⋯=a iM+1,此时有:a iM+1+1=M+1>M,矛盾.故对于任意的正整数M,必存在k∈N∗,使得a k>M.证法二:假设存在正整数M,使得对任意的k∈N∗,a k≤M,由题意,a k∈1,2,3,⋯,M,故数列a n至多有M个不同的取值,对任意的正整数m,数列a n中至多有M项的值为m,事实上若数列a n中至少有M+1项的值为m,其M+1项为a i1,a i2,a i3,⋯,a iM−1,a iM,a iM+1,此时有:a iM+1+1=M+1>M,矛盾.故数列a n至多有M2项,这与数列a n有无穷多项矛盾.故对于任意的正整数M,必存在k∈N∗,使得a k>M.(3)充分性:若a1=1,则数列a n的项依次为1,1,2,1,3,1,4,1,⋯,k−2,1,k−1,1,k,1,⋯特别地,数列a n的通项公式为a n=k,n=2k−11,n=2k,即a n=n+12,n=2k−11,n=2k,故对任意的n∈N∗,(1)若n为偶数,则a n+2=a n=1,(2)若n为奇数,则a n+2=n+32>n+12=a n,综上,a n+2≥a n恒成立,特别地,取m=1有当n≥m时,恒有a n+2≥a n成立.必要性:方法一:假设存在a1=k k>1,使得“存在m∈N∗,当n≥m时,恒有a n+2≥a n成立”,则数列a n的前k2+1项为k,1,1,2,1,3,1,4,⋯,1,k−2,1,k−1,1,k⏟2k−1项,2,2,3,2,4,2,5,⋯,2,k−2,2,k−1,2,k⏟2k−3项,3,3,4,3,5,3,6,⋯,3,k−2,3,k−1,3,k⏟2k−5项,⋯,k−2,k−2,k−1,k−2,k⏟5项,k−1,k−1,k⏟3项,k后面的项顺次为k+1,1,k+1,2,k+1,3,⋯,k+1,k−2,k+1,k−1,k+1,k⏟2k项,k+2,1,k+2,2,k+2,3,⋯,k+2,k−2,k+2,k−1,k+2,k⏟2k项,k+3,1,k+3,2,k+3,3,⋯,k+3,k−2,k+3,k−1,k+3,k⏟2k项,⋯k+t,1,k+t,2,k+t,3,⋯,k+t,k−2,k+t,k−1,k+t,k⏟2k项,⋯故对任意的s=1,2,3,⋯,k−2,k−1,k,t∈N∗,a k2+1+2t−1k+2s−1=k+t,a k2+1+2t−1k+2s=s,对任意的m,取t=m2k+1,其中x表示不超过x的最大整数,则2kt>m,令n=k2+1+2kt,则n>m,此时a n=k,a n+2=1,有a n>a n+2,这与a n≤a n+2矛盾,故若存在m∈N∗,当n≥m时,恒有a n+2≥a n成立,必有a1=1.方法二:若存在m∈N∗,当n≥m时,a n+2≥a n恒成立,记max a1,a2,⋯,a m=s,由第Ⅱ问的结论可知:存在k∈N∗,使得a k>s(由s的定义知k≥m+1),不妨设a k是数列a n中第一个大于等于s+1的项,即a1,a2,⋯,a k−1均小于等于s,则a k+1=1,因为k−1≥m,所以a k+1≥a k−1,即1≥a k−1且a k−1为正整数,所以a k−1=1,记a k=t≥s+1,由数列a n的定义可知,在a1,a2,⋯,a k−1中恰有t项等于1,假设a1≠1,则可设a i1=a i2=⋯=a it=1,其中1<i1<i2<⋯<i t=k−1,考虑这t个1的前一项,即a i1−1,a i2−1,⋯,a it−1,因为它们均为不超过s的正整数,且t≥s+1,所以a i1−1,a i2−1,⋯,a it−1中一定存在两项相等,将其记为a,则数列a n中相邻两项恰好为a,1的情况至少出现2次,但根据数列a n的定义可知:第二个a的后一项应该至少为2,不能为1,所以矛盾!故假设a1≠1不成立,所以a1=1,即必要性得证!综上,“a1=1”是“存在m∈N∗,当n≥m时,恒有a n+2≥a n成立”的充要条件.。
北京市海淀区高三第一学期期末测试2017.1第二部分:知识运用(共两节,45分)第一节单项填空(共15小题;每小题1分,共15分)21. Things don’t always go as planned, ______ I still stay positive.A. orB. asC. butD. for22. —What a drive! I’m tired out.—No wonder! You have been driving for such a long time ______ taking a break.A. byB. withoutC. throughD. in23. The 24 solar terms(二十四节气) a great effect on Chinese people’s lives for thousandsof years.A. have hadB. hadC. haveD. had had24. ______ as a volunteer teacher in Tibet for a year, Linda has become more experienced.A. To workB. WorkingC. Having workedD. Worked25. Yesterday I went back to my primary school, ______ my teachers and I recalled our good olddays.A. whichB. thatC. whenD. where26. Li Hua’s parents hold different opinions on whether they should have ______ child.A. anotherB. otherC. othersD. the other27. Social media, like WeChat, ______ the way of communication nowadays.A. are changingB. changeC. changedD. were changing28. In big cities, young people often go to cafés with friends.A. relaxedB. relaxC. to relaxD. relaxing29. I usually sleep with the window open ______ it is really cold.A. ifB. unlessC. now thatD. in case30. Beijing’s new international airport ______ into use in 2019, according to the spokesperson.A. was putB. will putC. has putD. will be put31. I had to catch my flight. That was ______ I left Tom’s party so early yesterday.A. whatB. howC. whyD. when32. Jenny was practicing her speech in the hall when she heard her name ______.A. callingB. calledC. to callD. having called33. If you want to be on the school football team, you ______ train harder.A. canB. wouldC. mightD. must34. A long road tests a horse’s strength and a long-term task ______ a man’s heart.A. provesB. will proveC. is provingD. has proved35. If there were no cellphones, life ______ quite different because we depend too much on them.A. will beB. would beC. isD. were第二节完形填空(共20小题;每小题1.5分,共30分)I was the fool at school, regarded as a special needs student. I was termed as such. Obviously, because I was not interested in school and did not care for my __36__.Over time, I started to believe in my stupidity. I __37__ the fact that I was in special needs classes and poured it out as anger and depression. But one activity __38__ this view of myself: chess.I started to play chess with my father after school simply because I wanted to __39__ him at something. My father was a __40__ man, fond of physics, writing, religion, …, almost every __41__. He was called a walking dictionary. So, winning in chess against my father would be a __42__ that I had intellectual power. On the small chessboard, I had a chance to __43__ my so-called inability.Game after game, I wanted to beat my father even more. I started to study chess books and play against a chess computer to __44__ my skills. One weekend, I finally checkmated(将杀) my father on a ferry ride, which made me feel __45__ .Two years later, I became the second board on my school chess team, with our top board being the best high school player in the state. But before the tournament season, our top player __46__ to come. There came my chance to play as top board against the best players in other states.I was determined to show who I had become: a(n) __47__ person able to win with calculation, logic and will. My most __48__ game came in the final round. Our team was facing a high school which only excellent students attended. It was __49__ a match between a special needs student and a smart soul. My opponent(对手) was playing well and kept __50__ while I kept defending to keep my king safe. He spent long trying to break down my defenses, but could not find the final push. I __51__ with more defensive moves, trying to make it as difficult for him as possible. With little__52__ left, he started to make rapid moves. __53__ he could make the final decision, he ran out of time. Honestly, as his clock flag fell, I jumped up out of my seat and kissed the floor out of excitement. Of course it was not the most sportsmen-like __54__, but I could not control my emotions.While holding my winner’s cup, I knew I was not __55__. The inferiority complex(自卑感) had melted away, and I realized that underneath our thoughts, each person is a genius.36. A. habits B. grades C. plans D. benefits37. A. noticed B. explained C. accepted D. ignored38. A. changed B. supported C. questioned D. showed39. A. please B. comfort C. beat D. disturb40. A. smart B. strict C. quiet D. strong41. A. method B. topic C. event D. field42. A. dream B. lesson C. theory D. sign43. A. prove B. expose C. overcome D. promote44. A. teach B. sharpen C. choose D. invent45. A. overjoyed B. disappointed C. puzzled D. interested46. A. promised B. managed C. happened D. failed47. A. brave B. lucky C. active D. intelligent48. A. terrible B. memorable C. dangerous D. popular49. A. normally B. possibly C. actually D. partly50. A. attacking B. smiling C. pausing D. escaping51. A. returned B. quit C. won D. exchanged52. A. patience B. time C. energy D. wisdom53. A. Once B. Until C. Before D. Unless54. A. spirit B. thought C. comment D. behavior55. A. proud B. stupid C. bright D. lazy第三部分:阅读理解(共两节,40分)第一节(共15小题;每小题2分,共30分)AMy doorbell rings. On the step, I find the elderly Chinese lady, small and slight, holding the hand of a little boy. In her other hand, she holds a paper carrier bag.I know this lady. It is not her first visit. She is the boy’s grandmother, and her daughter bought the house next door last October.Her daughter, Nicole, speaks fluent English. But she is now in Shanghai, and her parents are here with the little boy. Nicole has obviously told her mother that I am having heart surgery soon, so her mother has decided I need more nutrients. (56题)I know what is inside the bag—a thermos with hot soup and a stainless-steel container with rice, vegetables and either chicken, meat or shrimp, sometimes with a kind of pancake. This has become an almost-daily practice.(57题) Communication between us is somewhat affected by the fact that she doesn’t speak English and all I can say in Chinese is hello. Once, she brought an iPad as well as the food. She pointed to the screen, which displayed a message from her daughter telling me that her mother wanted to know if the food was all right and whether it was too salty. I am not used to iPads, so she indicated I should go with her to her house. Then, she handed the iPad to her husband and almost immediately I found myself looking at Nicole in Shanghai and discussing her mother’s cooking and salt intake. Instantly, tears welled in my eyes.“Your mother just can’t be bringing me meals like this all the time,” I insisted. “I can hardly do dishes in return.”“Oh, no, Lucy.” Nicole said. “Mum doesn’t like western food. Don’t worry about it; she has to cook for the three of them anyway, and she wants to do it.”The doorbell keeps ringing and there is the familiar brown paper carrier bag, handed smilingly to me.I am now working on some more Chinese words—it’s the least I can do after such a display of kindness.“Thank you” is, of course, the first one. Somehow, it seems inadequate. (58题)56. The elderly Chinese lady visits Lucy regularly because______.A. Lucy pays her to deliver foodB. Lucy likes cooking Chinese foodC. she cares about Lucy’s state of healthD. she wants to make friends with Lucy57. Nicole’s mum took an iPad to Lucy’s home for_________.A. displayingB. communicatingC. cookingD. chatting58. In this passage Lucy mainly expresses her ______.A. preference for the Chinese foodB. gratitude to the Chinese familyC. love of the advanced technologyD. affection for the Chinese languageBChinese Emoji (表情符号) Circles Globe (62题)“Funny”, a made-in-China emoji, seems to have recently moved beyond China. Now, it is more than an emoji, but a cultural expansion.●Reaching Global MarketsA series of “funny” emoji-based bolsters (抱枕) have attracted the attention of Japanese customers. Even if one bolster is more than three times as expensive as in China, it doesn’t kill their desires to buy it. One Japanese customer Miki said, “They are just so cute and I bought three bolsters at one time for my family. And every time I see them, my mood just brightens suddenly.” (59题)A Japanese netizen Kiro Kara said, “I think the emoji implies very complicated meanings. My dad will send it when he doesn’t agree with someone but he has to say something and behave politely.”●Addition to Domestic Social MediaCompared with Japanese impressions of the “funny” emoji, Chinese netizens prefer to use the emoji to tease one another on social media.One commonly seen online comment is, “We strongly suggest stopping the usage of the emoji. Because every time other people send me the emoji, I feel very uncomfortable and consider myself as a fool.”Regarded as the most popular emoji, the “funny” emoji has received much attention since its release in 2013. In fact, the “funny” emoji is the updated version of its original one; “funny” has a smiley mouth, two eyebrows and a naughty look. All these characteristics present users a sense of satire (讽刺). (60题)●In Everyday Use AbroadIt’s not the first time the Chinese emoji takes the world stage. Earlier this year, one emoji from the Chinese basketball celebrity Yao Ming has been spread through the Middle East region. In a city in southern Egypt, Yao’s smiling emoji has appeared frequently in local traffic signs to remind people the road ahead is one-way. Many locals do not know Yao Ming but are familiar with his emoji and nickname “Chinese Funny Face”.As a new online language, emojis have become a necessary part of people’s daily life, helping people express their views in a more vivid and precise way. (61题) Also, it can help foreigners learn about Chinese culture. But how to properly use “the fifth innovation in China” without hurtingothers and turn them into commercial advantages still needanswers.59. Why do the bolsters attract Miki’s attention?A. They are inexpensive.B. They helpreach an agreement.C. They help brighten the mood.D. They are helpful to express desire.60. According to the passage, which of the following is the latest “funny” emoji?A. B. C. D.61. Emojis are so popular worldwide mainly because people use them to ______.A. express their views more vividlyB. present their sense of satire directlyC. imply very complicated meanings properlyD. tease one another on social media purposely62. The main purpose of the text is to ______.A. promote the emoji worldwideB. teach us how to use the emojiC. explain the meaning the emojiD. show us the popularity of the emojiCEvery year billions of pounds are spent on hair loss treatment. If we succeed in curing hair loss with 3D printed hair follicles(毛囊), it will be a huge revolution.L’Oreal, the cosmetics firm is partnering with a French bio-printing company called Poietis, which has developed a form of laser(激光) printing for cell-based objects. Poietis’ technique begins with the creation of a digital map that determines where living cells and other tissue components should be placed to create the desired biological structure. This involves how the cells are expected to grow over time. The on the digital map is then turned into instructions for the printing equipment, so that it can lay down tiny droplets made out of the cell-based "bio ink" one layer at a time. The printing process involves bouncing a pulsing laser off a mirror and through a lens, so that when it hits a ribbon(色带) containing the bio ink, a droplet of the matter falls into place. About 10,000 of these micro-droplets are created every second. (63题)It typically takes about 10 minutes to print a piece of skin 1cm wide by 0.5mm thick. However, since hair follicles are complex and consist of 15 different cells in a structure, they may take longer.Poietis is not the only company working on bio-printing, but most others use another way, which involves pushing a bio-ink through a nozzle(喷嘴), rather than lasers to build their tissue.Poietis suggests its technique puts less stress on the biological matter, meaning there is less risk of causing it damage. (64题)Alopecia UK—a charity that provides support and advice about hair loss—has mixed feelings about the development. “It is encouraging to know that (66题)companies such as L’Oreal are investing in technology that may help those with hair loss in the future,” said spokeswoman Amy Johnson.(66题) “However, we would suggest it’s still very early to be getting excited about what this potentially could mean for those with medical hair loss. At this point it is unclear as to whether this technology could benefit those with all types of hair loss.” (65题)“Also, if this new technology does lead to a treatment option, given the high costs of existing hair transplant procedures, how many people will be able to realistically afford any new technological advances that may become available? (65题) As with any other research and development into processes that may be able to help those with hair loss, we watch with great interest.”63. What does Paragraph 2 mainly tell us?A. How the printing process is carried out.B. Where the living cells should be placed.C. How long the cells are expected to grow.D. What the printing equipment is made up of.64. What does the underlined word “it” in Paragraph 4 refer to?A. hair follicleB. biological matterC. nozzleD. bio-ink65. The passage implies that the new technology may ______.A. meet some practical challengesB. help people with hair loss at presentC. offer solutions to all problems of hair lossD. cost a large sum of money to transplant hair66. What is Amy Johnson’s attitude towards the new technology?A. Disapproving.B. Optimistic.C. Cautious.D. Negative.DThere is no doubt eCommerce is growing, and it will continue to grow. However, physical stores would not die as a result of the rise of eCommerce, at least not in the near future. The idea that eCommerce is taking over physical stores has already misguided many people. Physical stores are far from vanishing, and there are some solid reasons for it. (69题)The projections for online spending is optimistic with $150 billion expected to be spent in the coming three years, yet we are also expecting (67题) $300 billion in spending at physical stores in the same duration. Do you still think that physical-store shopping is too small to sustain the eCommerce blow?Even though consumers are staying away from physical stores that follow older concepts, yet we are seeing the rise of fresh concept stores all around the US. We are seeing innovative and attractive success stories of physical stores, ranging from clothes stores to restaurants to health spas. It would be easy to assume that this trend will continue.Indeed, many shopping malls are dying, yet there are still those shopping centers that areperforming well. You can see this for yourself by visiting shopping malls near you. What I want to emphasize here is that not all shopping centers are made equal, just like not all eCommerce retailers are made equal. Both shopping malls and eCommerce sites can lose business if they fail to maintain productivity through improvements and innovations. (68题) When you visit shopping centers that are serious about their business, you would see their shops and parking lots packed.On the other hand, even e -tailers like Amazon have experimented with pop -up shopping concepts. It is important to bear in mind that consumers prefer face -to -face interactions instead of online interactions during shopping, meaning that physical stores are going to stay there.Still, eCommerce retailers are seeing all of their excitement disappear as they settle the sales tax problem associated with e -tailing. As of now, five states of America have already imposed sales tax on purchases through eCommerce sites, and e -tailers in those states have already witnessed 6 to 12 percent decrease in sales.This reinforces the fact that physical stores are here to stay, and if you are still undervaluing their growth, you are omitting a huge chunk of the retail representation. (69题)67. The underlined word "projections" in Paragraph 2 probably means____.A. intentionsB. assessmentsC. performancesD. predictions68. What can we infer from the passage?A. E -tailers are more creative businesses.B. Fresh concepts help build good business.C. Fewer consumers will visit physical stores.D. Physical stores can’t stand the blow of eCommerce.69. What is the best title for this passage?A. Is Offline Spending Greater Than Online Spending?B. Online Stores V .S. Physical Stores—What’s the Difference?C. Will Physical Stores replace eCommerce in the Near Future ?D. Does eCommerce Success Mean Physical Stores Will Disappear?70. Which of the following shows the development of the passage?A. B. C.D. P: Point Sp: Sub -point (次要点) C: ConclusionCP Sp 2Sp 1 P 2 C P 1 Sp 2 Sp 1 P 2 CP Sp 2 Sp 1 P 3 C P 1 CP P 2 C P 1 Sp 2 Sp 1 CP PPSp 2 Sp 1 P 2 C P 1第二节(共5小题;每小题2分,共10分)根据短文内容,从短文后的七个选项中选出能填入空白处的最佳选项。
海淀区高三年级第一学期末练习物 理 2017.1说明:本试卷共8页,共100分。
考试时长90分钟。
考生务必将答案写在答题纸上,在试卷上作答无效。
考试结束后,将本试卷和答题纸一并交回。
一、本题共10小题,每小题3分,共30分。
在每小题给出的四个选项中,有的小题只有一个选项是正确的,有的小题有多个选项是正确的。
全部选对的得3分,选不全的得2分,有选错或不答的得0分。
把你认为正确答案填涂在答题纸上。
1.真空中两相同的带等量异号电荷的金属小球A 和B (均可看做点电荷),分别固定在两处,它们之间的距离远远大于小球的直径,两球间静电力大小为 F 。
现用一个不带电的同样的绝缘金属小球C 与A 接触,然后移开C ,此时A 、B 球间的静电力大小为 A .2F B .F C .32F D .2F 2.用绝缘柱支撑着贴有小金属箔的导体A 和B ,使它们彼此接触,起初它们不带电,贴在它们下部的并列平行双金属箔是闭合的。
现将带正电荷的物体C 移近导体A ,发现金属箔都张开一定的角度,如图1所示,则 A .导体B 下部的金属箔感应出负电荷 B .导体B 下部的金属箔感应出正电荷C .导体 A 和B 下部的金属箔都感应出负电荷D .导体 A 感应出负电荷,导体B 感应出等量的正电荷3.如图2所示,M 、N 为两个带有等量异号电荷的点电荷,O 点是它们之间连线的中点,A 、B 是M 、N 连线中垂线上的两点,A 点距O 点较近。
用E O 、E A 、E B 和φO 、φA 、φB 分别表示O 、A 、B中正确的是A .E O等于0B .E A 一定大于E BC .φA 一定大于φBD .将一电子从O 点沿中垂线移动到A 点,电场力一定不做功4.在电子技术中,从某一装置输出的交流信号常常既含有高频成份,又含有低频成份。
为了在后面一级装置中得到高频成份或低频成份,我们可以在前面一级装置和后面一级装置之间设计如图3所示的电路。
2017海淀区高三年级第一学期末练习物 理1.真空中两相同的带等量异号电荷的金属小球A 和B (均可看做点电荷),分别固定在两处,它们之间的距离远远大于小球的直径,两球间静电力大小为 F 。
现用一个不带电的同样的绝缘金属小球C 与A 接触,然后移开C ,此时A 、B 球间的静电力大小为A .2FB .FC .32F D .2F 2.用绝缘柱支撑着贴有小金属箔的导体A 和B ,使它们彼此接触,起初它们不带电,贴在它们下部的并列平行双金属箔是闭合的。
现将带正电荷的物体C 移近导体A ,发现金属箔都张开一定的角度,如图1所示,则A .导体B 下部的金属箔感应出负电荷 B .导体B 下部的金属箔感应出正电荷C .导体 A 和B 下部的金属箔都感应出负电荷D .导体 A 感应出负电荷,导体B 感应出等量的正电荷3.如图2所示,M 、N 为两个带有等量异号电荷的点电荷,O 点是它们之间连线的中点,A 、B 是M 、N 连线中垂线上的两点,A 点距O 点较近。
用E O 、E A 、E B 和φO 、φA 、φB 分别表示O 、A 、B 三点的电场强度的大小和电势,下列说法中正确的是A .E O 等于0B .E A 一定大于E BC .φA 一定大于φBD .将一电子从O 点沿中垂线移动到A 点,电场力一定不做功4.在电子技术中,从某一装置输出的交流信号常常既含有高频成份,又含有低频成份。
为了在后面一级装置中得到高频成份或低频成份,我们可以在前面一级装置和后面一级装置之间设计如图3所示的电路。
关于这种电路,下列说法中正确的是A .要使“向后级输出”端得到的主要是高频信号,应该选择图3甲所示电路B .要使“向后级输出”端得到的主要是高频信号,应该选择图3乙所示电路C .要使“向后级输出”端得到的主要是低频信号,应该选择图3甲所示电路D .要使“向后级输出”端得到的主要是低频信号,应该选择图3乙所示电路5.如图4所示,一理想变压器的原、副线圈匝数分别为2200匝和110匝,将原线圈接在输出电压u =2202sin100πt (V )的交流电源两端。
2017-2018学年北京市海淀区高三(上)期末数学试卷(理科)一、选择题共8小题,每小题5分,共40分.在每小题列出的四个选项中,选出符合题目要求的一项.1.(5分)复数=()A.2﹣i B.2+i C.﹣2﹣i D.﹣2+i2.(5分)在极坐标系中Ox,方程ρ=2sinθ表示的圆为()A.B.C.D.3.(5分)执行如图所示的程序框图,输出的k值为()A.4 B.5 C.6 D.74.(5分)设m是不为零的实数,则“m>0”是“方程表示的曲线为双曲线”的()A.充分不必要条件 B.必要不充分条件C.充分必要条件D.既不充分也不必要条件5.(5分)已知直线x﹣y+m=0与圆O:x2+y2=1相交于A,B两点,且△AOB为正三角形,则实数m的值为()A.B.C.或D.或6.(5分)从编号分别为1,2,3,4,5,6的六个大小完全相同的小球中,随机取出三个小球,则恰有两个小球编号相邻的概率为()A.B.C.D.7.(5分)某三棱锥的三视图如图所示,则下列说法中:①三棱锥的体积为②三棱锥的四个面全是直角三角形③三棱锥的四个面的面积最大的是所有正确的说法是()A.①B.①②C.②③D.①③8.(5分)已知点F为抛物线C:y2=2px(p>0)的焦点,点K为点F关于原点的对称点,点M在抛物线C上,则下列说法错误的是()A.使得△MFK为等腰三角形的点M有且仅有4个B.使得△MFK为直角三角形的点M有且仅有4个C.使得的点M有且仅有4个D.使得的点M有且仅有4个二、填空题共6小题,每小题5分,共30分.9.(5分)点(2,0)到双曲线的渐近线的距离是.10.(5分)已知公差为1的等差数列{a n}中,a1,a2,a4成等比数列,则{a n}的前100项和为.11.(5分)设抛物线C:y2=4x的顶点为O,经过抛物线C的焦点且垂直于x轴的直线和抛物线C交于A,B两点,则=.12.(5分)已知(5x﹣1)n的展开式中,各项系数的和与各项二项式系数的和之比为64:1,则n=.13.(5分)已知正方体ABCD﹣A1B1C1D1的棱长为,点M是棱BC的中点,点P在底面ABCD内,点Q在线段A1C1上,若PM=1,则PQ长度的最小值为.14.(5分)对任意实数k,定义集合.①若集合D k表示的平面区域是一个三角形,则实数k的取值范围是;②当k=0时,若对任意的(x,y)∈D k,有y≥a(x+3)﹣1恒成立,且存在(x,y)∈D k,使得x﹣y≤a成立,则实数a的取值范围为.三、解答题共6小题,共80分.解答应写出文字说明,演算步骤或证明过程.15.(13分)如图,在△ABC中,点D在AC边上,且AD=3BC,AB=.(Ⅰ)求DC的值;(Ⅱ)求tan∠ABC的值.16.(13分)据中国日报网报道:2017年11月13日,TOP500发布的最新一期全球超级计算机500强榜单显示,中国超算在前五名中占据两席,其中超算全球第一“神威太湖之光”完全使用了国产品牌处理器.为了了解国产品牌处理器打开文件的速度,某调查公司对两种国产品牌处理器进行了12次测试,结果如下(数值越小,速度越快,单位是MIPS)(Ⅰ)从品牌A的12次测试中,随机抽取一次,求测试结果小于7的概率;(Ⅱ)从12次测试中,随机抽取三次,记X为品牌A的测试结果大于品牌B的测试结果的次数,求X的分布列和数学期望E(X);(Ⅲ)经过了解,前6次测试是打开含有文字和表格的文件,后6次测试是打开含有文字和图片的文件.请你依据表中数据,运用所学的统计知识,对这两种国产品牌处理器打开文件的速度进行评价.17.(14分)如图1,梯形ABCD中,AD∥BC,CD⊥BC,BC=CD=1,AD=2,E为AD中点.△A1ED为正三角形,将△ABE沿BE翻折到△A1BE的位置,如图2,△A1ED为正三角形.(Ⅰ)求证:平面△A1DE⊥平面BCDE;(Ⅱ)求直线A1B与平面A1CD所成角的正弦值;(Ⅲ)设M,N分别为A1E和BC的中点,试比较三棱锥M﹣A1CD和三棱锥N﹣A1CD(图中未画出)的体积大小,并说明理由.18.(13分)已知椭圆C:x2+2y2=9,点P(2,0)(Ⅰ)求椭圆C的短轴长和离心率;(Ⅱ)过(1,0)的直线l与椭圆C相交于两点M,N,设MN的中点为T,判断|TP|与|TM|的大小,并证明你的结论.19.(14分)已知函数f(x)=2e x﹣ax2﹣2x﹣2.(Ⅰ)求曲线y=f(x)在点(0,f(0))处的切线方程;(Ⅱ)当a≤0时,求证:函数f(x)有且仅有一个零点;(Ⅲ)当a>0时,写出函数f(x)的零点的个数.(只需写出结论)20.(13分)无穷数列{a n}满足:a1为正整数,且对任意正整数n,a n+1为前n项a1,a2,…,a n中等于a n的项的个数.(Ⅰ)若a1=2,请写出数列{a n}的前7项;(Ⅱ)求证:对于任意正整数M,必存在k∈N*,使得a k>M;(Ⅲ)求证:“a1=1”是“存在m∈N*,当n≥m时,恒有a n+2≥a n成立”的充要条件.2017-2018学年北京市海淀区高三(上)期末数学试卷(理科)参考答案与试题解析一、选择题共8小题,每小题5分,共40分.在每小题列出的四个选项中,选出符合题目要求的一项.1.(5分)复数=()A.2﹣i B.2+i C.﹣2﹣i D.﹣2+i【解答】解:=.故选:A.2.(5分)在极坐标系中Ox,方程ρ=2sinθ表示的圆为()A.B.C.D.【解答】解:方程ρ=2sinθ,整理得:ρ2=2ρsinθ,转化为:x2+y2﹣2y=0,即:x2+(y﹣1)2=1.根据圆在极坐标系中的位置,只有D符合.故选:D.3.(5分)执行如图所示的程序框图,输出的k值为()A.4 B.5 C.6 D.7【解答】解:模拟程序的运行,可得a=1,k=1不满足条件a>10,执行循环体,a=2,k=2不满足条件a>10,执行循环体,a=4,k=3不满足条件a>10,执行循环体,a=8,k=4不满足条件a>10,执行循环体,a=16,k=5满足条件a>10,退出循环,输出k的值为5.故选:B.4.(5分)设m是不为零的实数,则“m>0”是“方程表示的曲线为双曲线”的()A.充分不必要条件 B.必要不充分条件C.充分必要条件D.既不充分也不必要条件【解答】解:方程表示的曲线为双曲线⇔m≠0.∴“m>0”是“方程表示的曲线为双曲线”的充分不必要条件.故选:A.5.(5分)已知直线x﹣y+m=0与圆O:x2+y2=1相交于A,B两点,且△AOB为正三角形,则实数m的值为()A.B.C.或D.或【解答】解:直线x﹣y+m=0与圆O:x2+y2=1相交于A,B两点,且△AOB为正三角形,则:△AOB的边长为1,则:圆心(0,0)到直线x﹣y+m=0的距离d=,解得:m=±.故选:D.6.(5分)从编号分别为1,2,3,4,5,6的六个大小完全相同的小球中,随机取出三个小球,则恰有两个小球编号相邻的概率为()A.B.C.D.【解答】解:从编号分别为1,2,3,4,5,6的六个大小完全相同的小球中,随机取出三个小球,基本事件总数n==20,恰有两个小球编号相邻包含的基本事件个数m=12个,∴恰有两个小球编号相邻的概率为p==.故选:C.7.(5分)某三棱锥的三视图如图所示,则下列说法中:①三棱锥的体积为②三棱锥的四个面全是直角三角形③三棱锥的四个面的面积最大的是所有正确的说法是()A.①B.①②C.②③D.①③【解答】解:依据三视图,可得该几何体,如图三棱锥P﹣ABC,AC=BC=1,AB=.PA=PB,面PC⊥面ABC,P到面ABC的距离为1.①三棱锥的体积为=,正确;②三棱锥的面PAB不是直角三角形,错;③三棱锥的四个面的面积最大的是△PAB,PA=BP═AB=,其面积S=,故错.故选:A8.(5分)已知点F为抛物线C:y2=2px(p>0)的焦点,点K为点F关于原点的对称点,点M在抛物线C上,则下列说法错误的是()A.使得△MFK为等腰三角形的点M有且仅有4个B.使得△MFK为直角三角形的点M有且仅有4个C.使得的点M有且仅有4个D.使得的点M有且仅有4个【解答】解:由△MFK为等腰三角形,若KF=MF,则M有两个点;若MK=MF,则不存在,若MK=FK,则M有两个点,则使得△MFK为等腰三角形的点M有且仅有4个;由△MFK中∠MFK为直角的点M有两个;∠MKF为直角的点M不存在;∠FMK为直角的点M有两个,则使得△MFK为直角三角形的点M有且仅有4个;若的M在第一象限,可得直线MK:y=x+,代入抛物线的方程可得x2﹣px+=0,解得x=,由对称性可得M在第四象限只有一个,则满足的M有且只有2个;使得的点M在第一象限,可得直线MK:y=(x+),代入抛物线的方程,可得x2﹣5px+=0,△=25p2﹣p2=24p2>0,可得点M有2个;若M在第四象限,由对称性可得也有2个,则使得的点M有且只有4个.故选:C.二、填空题共6小题,每小题5分,共30分.9.(5分)点(2,0)到双曲线的渐近线的距离是.【解答】解:双曲线的渐近线为:y=,点(2,0)到双曲线的渐近线的距离是:=.故答案为:.10.(5分)已知公差为1的等差数列{a n}中,a1,a2,a4成等比数列,则{a n}的前100项和为5050.【解答】解:在公差为1的等差数列{a n}中,由a1,a2,a4成等比数列,得:(a1+1)2=a1(a1+3),即a1=1.∴S100=100×=5050.故答案为:5050.11.(5分)设抛物线C:y2=4x的顶点为O,经过抛物线C的焦点且垂直于x轴的直线和抛物线C交于A,B两点,则=2.【解答】解:抛物线C:y2=4x的焦点坐标(1,0),经过抛物线C的焦点且垂直于x轴的直线和抛物线C交于A,B两点,则A(1,2),B(1,﹣2);=(2,0);则=2.故答案为:2.12.(5分)已知(5x﹣1)n的展开式中,各项系数的和与各项二项式系数的和之比为64:1,则n=6.【解答】解:由题意可得=2n=64,∴n=6,故答案为:6.13.(5分)已知正方体ABCD﹣A1B1C1D1的棱长为,点M是棱BC的中点,点P在底面ABCD内,点Q在线段A1C1上,若PM=1,则PQ长度的最小值为.【解答】解:如图,点P在以M为圆心,1以半径的位于平面ABCD内的半圆上,连结A1C1、B1D1,交于点O,取B1C1中点N,OC1中点Q,连结QN,取QN中点E,连结PE,PQ,此时PQ长度取最小值,∵正方体ABCD﹣A1B1C1D1的棱长为,点M是棱BC的中点,点P在底面ABCD 内,点Q在线段A1C1上,PM=1,∴PM=EN=1,∵ON=OB1=B1D1==2,∴QE=2﹣1=1,又PE=CC1=4,∴PQ长度的最小值为:==.故答案为:.14.(5分)对任意实数k,定义集合.①若集合D k表示的平面区域是一个三角形,则实数k的取值范围是(﹣1,1);②当k=0时,若对任意的(x,y)∈D k,有y≥a(x+3)﹣1恒成立,且存在(x,y)∈D k,使得x﹣y≤a成立,则实数a的取值范围为[﹣2,] .【解答】解:①作出不等式组所表示的平面区域,如图所示,若不等式组表示的平面区域是一个三角形,观察图形可得只要满足﹣1<k<1时满足条件,②对任意的(x,y)∈D k,有y≥a(x+3)﹣1恒成立,则a≤恒成立,因为表示与定点(﹣3,﹣1)的斜率,当过点B(2,0)时,此时有最小值,最小值为,即a≤,存在(x,y)∈D k,使得x﹣y≤a成立,则a≥(x﹣y)min,平移目标函数y=x﹣a,当直线和y=x+2重合时,此时x﹣y最小,最小值为﹣2,则a≥﹣2,综上所述a的取值范围为[﹣2,]故答案为:①(﹣1,1)②三、解答题共6小题,共80分.解答应写出文字说明,演算步骤或证明过程.15.(13分)如图,在△ABC中,点D在AC边上,且AD=3BC,AB=.(Ⅰ)求DC的值;(Ⅱ)求tan∠ABC的值.【解答】(本小题13分)解:(Ⅰ)如图所示,,….(1分)故∠DBC=∠C,DB=DC….(2分)设DC=x,则DB=x,DA=3x.在△ADB中,由余弦定理AB2=DA2+DB2﹣2DA•DB•cos∠ADB….(3分)即,….(4分)解得x=1,即DC=1.….(5分)(Ⅱ)方法一.在△ADB中,由AD>AB,得∠ABD>∠ADB=60°,故….(6分)在△ABC中,由正弦定理….(7分)即,故,….(9分)由,得,….(11分)…(13分)方法二.在△ADB中,由余弦定理….(7分)由∠ABD∈(0,π),故….(9分)故….(11分)故…(13分)16.(13分)据中国日报网报道:2017年11月13日,TOP500发布的最新一期全球超级计算机500强榜单显示,中国超算在前五名中占据两席,其中超算全球第一“神威太湖之光”完全使用了国产品牌处理器.为了了解国产品牌处理器打开文件的速度,某调查公司对两种国产品牌处理器进行了12次测试,结果如下(数值越小,速度越快,单位是MIPS )(Ⅰ)从品牌A 的12次测试中,随机抽取一次,求测试结果小于7的概率; (Ⅱ)从12次测试中,随机抽取三次,记X 为品牌A 的测试结果大于品牌B 的测试结果的次数,求X 的分布列和数学期望E (X );(Ⅲ)经过了解,前6次测试是打开含有文字和表格的文件,后6次测试是打开含有文字和图片的文件.请你依据表中数据,运用所学的统计知识,对这两种国产品牌处理器打开文件的速度进行评价. 【解答】(本小题13分)解:(Ⅰ)从品牌A 的12次测试中,测试结果打开速度小于7的文件有: 测试1、2、5、6、9、10、11,共7次 设该测试结果打开速度小于7为事件A ,因此….(3分)(Ⅱ)12次测试中,品牌A 的测试结果大于品牌B 的测试结果的次数有: 测试1、3、4、5、7、8,共6次 随机变量X 所有可能的取值为:0,1,2,3….(7分)随机变量X 的分布列为….(8分)….(10分)(Ⅲ)本题为开放问题,答案不唯一,在此给出评价标准,并给出可能出现的答案情况,阅卷时按照标准酌情给分.给出明确结论,(1分);结合已有数据,能够运用以下8个标准中的任何一个陈述得出该结论的理由,(2分).…(13分).标准1:会用前6次测试品牌A、品牌B的测试结果的平均值与后6次测试品牌A、品牌B的测试结果的平均值进行阐述(这两种品牌的处理器打开含有文字与表格的文件的测试结果的平均值均小于打开含有文字和图片的文件的测试结果平均值;这两种品牌的处理器打开含有文字与表格的文件的平均速度均快于打开含有文字和图片的文件的平均速度)标准2:会用前6次测试品牌A、品牌B的测试结果的方差与后6次测试品牌A、品牌B的测试结果的方差进行阐述(这两种品牌的处理器打开含有文字与表格的文件的测试结果的方差均小于打开含有文字和图片的文件的测试结果的方差;这两种品牌的处理器打开含有文字与表格的文件速度的波动均小于打开含有文字和图片的文件速度的波动)标准3:会用品牌A前6次测试结果的平均值、后6次测试结果的平均值与品牌B前6次测试结果的平均值、后6次测试结果的平均值进行阐述(品牌A前6次测试结果的平均值大于品牌B前6次测试结果的平均值,品牌A后6次测试结果的平均值小于品牌B后6次测试结果的平均值,品牌A打开含有文字和表格的文件的速度慢于品牌B,品牌A打开含有文字和图形的文件的速度快于品牌B)标准4:会用品牌A前6次测试结果的方差、后6次测试结果的方差与品牌B前6次测试结果的方差、后6次测试结果的方差进行阐述(品牌A前6次测试结果的方差大于品牌B前6次测试结果的方差,品牌A后6次测试结果的方差小于品牌B后6次测试结果的方差,品牌A打开含有文字和表格的文件的速度波动大于品牌B,品牌A打开含有文字和图形的文件的速度波动小于品牌B)标准5:会用品牌A这12次测试结果的平均值与品牌B这12次测试结果的平均值进行阐述(品牌A这12次测试结果的平均值小于品牌B这12次测试结果的平均值,品牌A打开文件的平均速度快于B)标准6:会用品牌A这12次测试结果的方差与品牌B这12次测试结果的方差进行阐述(品牌A这12次测试结果的方差小于品牌B这12次测试结果的方差,品牌A打开文件速度的波动小于B)标准7:会用前6次测试中,品牌A测试结果大于(小于)品牌B测试结果的次数、后6次测试中,品牌A测试结果大于(小于)品牌B测试结果的次数进行阐述(前6次测试结果中,品牌A小于品牌B的有2次,占1/3.后6次测试中,品牌A小于品牌B的有4次,占2/3.故品牌A打开含有文字和表格的文件的速度慢于B,品牌A打开含有文字和图片的文件的速度快于B)标准8:会用这12次测试中,品牌A测试结果大于(小于)品牌B测试结果的次数进行阐述(这12次测试结果中,品牌A小于品牌B的有6次,占1/2.故品牌A和品牌B打开文件的速度相当)参考数据17.(14分)如图1,梯形ABCD中,AD∥BC,CD⊥BC,BC=CD=1,AD=2,E为AD中点.△A1ED为正三角形,将△ABE沿BE翻折到△A1BE的位置,如图2,△A1ED为正三角形.(Ⅰ)求证:平面△A1DE⊥平面BCDE;(Ⅱ)求直线A1B与平面A1CD所成角的正弦值;(Ⅲ)设M,N分别为A1E和BC的中点,试比较三棱锥M﹣A1CD和三棱锥N﹣A1CD(图中未画出)的体积大小,并说明理由.【解答】(Ⅰ)证明:∵BE⊥A1E,BE⊥DE,且A1E∩DE=E,A1E,DE⊂平面A1DE,∴BE⊥平面A1DE,∵BE⊂平面BCDE,∴平面A1DE⊥平面BCDE;(Ⅱ)解:在平面A1DE内过E作ED的垂线,由BE⊥平面A1DE,建系如图.则,B(1,0,0),C(1,1,0),D(0,1,0),E(0,0,0).,,,设平面A 1CD的法向量为,则,即,令z=1,得,∴.∴A1B与平面A1CD所成角的正弦值为;(Ⅲ)解:三棱锥M﹣A1CD和三棱锥N﹣A1CD的体积相等.理由如:方法一、由,,知,则.∵MN⊄平面A1CD,∴MN∥平面A1CD.故点M、N到平面A1CD的距离相等,有三棱锥M﹣A1CD和N﹣A1CD同底等高,则体积相等.方法二、如图,取DE中点P,连接MP,NP,MN.∵在△A1DE中,M,P分别是A1E,DE的中点,∴MP∥A1D,在正方形BCDE中,∵N,P分别是BC,DE的中点,∴NP∥CD,∵MP∩NP=P,MP,NP⊂平面MNP,A1D,CD⊂平面A1CD,∴平面MNP∥平面A1CD.∵MN⊂平面MNP,∴MN∥平面A1CD.故点M、N到平面A1CD的距离相等,有三棱锥M﹣A1CD和N﹣A1CD同底等高,则体积相等.18.(13分)已知椭圆C:x2+2y2=9,点P(2,0)(Ⅰ)求椭圆C的短轴长和离心率;(Ⅱ)过(1,0)的直线l与椭圆C相交于两点M,N,设MN的中点为T,判断|TP|与|TM|的大小,并证明你的结论.【解答】(本小题13分)解:(Ⅰ)椭圆C:x2+2y2=9,化为:,故a2=9,,,有a=3,.…..(3分)椭圆C的短轴长为,离心率为.…..(5分)(Ⅱ)结论是:|TP|<|TM|.…..(6分)设直线l:x=my+1,M(x1,y1),N(x2,y2),,整理得:(m2+2)y2+2my﹣8=0…..(8分)△=(2m)2+32(m2+2)=36m2+64>0故,…..(10分)=(x1﹣2)(x2﹣2)+y1y2…..(11分)=(my1﹣1)(my2﹣1)+y1y2=(m2+1)y1y2﹣m(y1+y2)+1==<0…..(12分)故∠MPN>90°,即点P在以MN为直径的圆内,故|TP|<|TM|…..(13分)19.(14分)已知函数f(x)=2e x﹣ax2﹣2x﹣2.(Ⅰ)求曲线y=f(x)在点(0,f(0))处的切线方程;(Ⅱ)当a≤0时,求证:函数f(x)有且仅有一个零点;(Ⅲ)当a>0时,写出函数f(x)的零点的个数.(只需写出结论)【解答】解:(Ⅰ)因为函数f(x)=2e x﹣ax2﹣2x﹣2,所以f′(x)=2e x﹣2ax﹣2,故f(0)=0,f'(0)=0,曲线y=f(x)在x=0处的切线方程为y=0;(Ⅱ)证明:当a≤0时,令g(x)=f′(x)=2e x﹣2ax﹣2,则g′(x)=2e x﹣2a>0,故g(x)是R上的增函数.由g(0)=0,故当x<0时,g(x)<0,当x>0时,g(x)>0.即当x<0时,f′(x)<0,当x>0时,f′(x)>0.故f(x)在(﹣∞,0)单调递减,在(0,+∞)单调递增.函数f(x)的最小值为f(0).由f(0)=0,故f(x)有且仅有一个零点.(Ⅲ)当a=1时,f(x)有一个零点;当a>0且a≠1时,f(x)有两个零点.20.(13分)无穷数列{a n}满足:a1为正整数,且对任意正整数n,a n+1为前n项a1,a2,…,a n中等于a n的项的个数.(Ⅰ)若a1=2,请写出数列{a n}的前7项;(Ⅱ)求证:对于任意正整数M,必存在k∈N*,使得a k>M;(Ⅲ)求证:“a1=1”是“存在m∈N*,当n≥m时,恒有a n+2≥a n成立”的充要条件.【解答】解:(Ⅰ)2,1,1,2,2,3,1 …,证明(Ⅱ)假设存在正整数M,使得对任意的k∈N*,a k≤M.由题意,a k∈{1,2,3,…,M}考虑数列{a n}的前M2+1项:a1,a2,a3,…,其中至少有M+1项的取值相同,不妨设此时有:,矛盾.故对于任意的正整数M,必存在k∈N*,使得a k>M.证明(Ⅲ)充分性:当a1=1时,数列{a n}为1,1,2,1,3,1,4,…,1,k﹣1,1,k,…特别地,a2k﹣1=k,a2k=1故对任意的n∈N*(1)若n为偶数,则a n+2=a n=1(2)若n为奇数,则综上,a n+2≥a n恒成立,特别地,取m=1有当n≥m时,恒有a n+2≥a n成立必要性:方法一:假设存在a1=k(k>1),使得“存在m∈N*,当n≥m时,恒有a n+2≥a n 成立”则数列{a n}的前k2+1项为k,1,1,2,1,3,1,4,…,1,k﹣1,1,k2,2,3,2,4,…,2,k﹣1,2,k3,3,4,…,3,k﹣1,3,k…k﹣2,k﹣2,k﹣1,k﹣2,kk﹣1,k﹣1,kk后面的项顺次为k+1,1,k+1,2,…,k+1,kk+2,1,k+2,2,…,k+2,kk+3,1,k+3,2,…,k+3,k…对任意的m,总存在n≥m,使得a n=k,a n+2=1,这与a n≤a n+2矛盾,故若存在m∈N*,当n≥m时,恒有a n≥a n成立,必有a1=1+2≥a n恒成立,记max{a1,a2,…,a m}=s.方法二:若存在m∈N*,当n≥m时,a n+2由第(2)问的结论可知:存在k∈N*,使得a k>s(由s的定义知k≥m+1)不妨设a k是数列{a n}中第一个大于等于s+1的项,即a1,a2,…,a k均小于等﹣1于s.=1.因为k﹣1≥m,所以a k+1≥a k﹣1,即1≥a k﹣1且a k﹣1为正整数,所以a k 则a k+1=1.﹣1记a k=t≥s+1,由数列{a n}的定义可知,在a1,a2,…,a k﹣1中恰有t项等于1.假设a 1≠1,则可设,其中1<i1<i2<…<i t=k﹣1,考虑这t个1的前一项,即,因为它们均为不超过s的正整数,且t≥s+1,所以中一定存在两项相等,将其记为a,则数列{a n}中相邻两项恰好为(a,1)的情况至少出现2次,但根据数列{a n}的定义可知:第二个a的后一项应该至少为2,不能为1,所以矛盾,故假设a1≠1不成立,所以a1=1,即必要性得证综上,“a1=1”是“存在m∈N*,当n≥m时,恒有a n+2≥a n成立”的充要条件.。
2016-2017学年北京市海淀区高三(上)期末数学试卷(理科)
一、选择题(共8小题,每小题5分,满分40分)
1.(5分)抛物线y2=2x的焦点到准线的距离为()
A.B.1 C.2 D.3
2.(5分)在极坐标系中,点(1,)与点(1,)的距离为()A.1 B.C.D.
3.(5分)如图程序框图所示的算法来自于《九章算术》,若输入a的值为16,b 的值为24,则执行该程序框图的结果为()
A.6 B.7 C.8 D.9
4.(5分)已知向量,满足,()=2,则=()
A.﹣ B.C.﹣2 D.2
5.(5分)已知直线l经过双曲线的一个焦点且与其一条渐近线平行,则直线l的方程可以是()
A.y=﹣B.y=C.y=2x﹣D.y=﹣2x+
6.(5分)设x,y满足,则(x+1)2+y2的最小值为()
A.1 B.C.5 D.9
7.(5分)在手绘涂色本的某页上画有排成一列的6条未涂色的鱼,小明用红、蓝两种颜色给这些鱼涂色,每条鱼只能涂一种颜色,两条相邻的鱼不都涂成红色,涂色后,既有红色鱼又有蓝色鱼的涂色方法种数为()
A.14 B.16 C.18 D.20
8.(5分)如图,已知正方体ABCD﹣A1B1C1D1的棱长为1,E,F分别是棱AD,B1C1上的动点,设AE=x,B1F=y,若棱DD1与平面BEF有公共点,则x+y的取值范围是()
A.[0,1]B.[,]C.[1,2]D.[,2]
二、填空题(共6小题,每小题5分,满分30分)
9.(5分)已知复数z满足(1+i)z=2,则z=.
10.(5分)(x2+)6的展开式中常数项是.(用数字作答)
11.(5分)若一个几何体由正方体挖去一部分得到,其三视图如图所示,则该
几何体的体积为.。
海淀区高三年级第一学期期末练习物理 2018.1说明:本试卷共8页,共100分。
考试时长90分钟。
考生务必将答案写在答题纸上,在试卷上作答无效。
考试结束后,将本试卷和答题纸一并交回。
一、本题共10小题,每小题3分,共30分。
在每小题给出的四个选项中,有的小题只有一个选项是正确的,有的小题有多个选项是正确的。
全部选对的得3分,选不全的得2分,有选错或不答的得0分。
把你认为正确答案填涂在答题纸上。
1. 放在绝缘支架上的两个相同金属球相距为d ,球的半径比d 小得多,分别带有q 和-3q 的电荷,相互作用力为F 。
现将这两个金属球接触,然后分开,仍放回原处,则它们的相互作用力将为 A .引力且大小为3F B. 斥力且大小为F /3 C .斥力且大小为2F D. 斥力且大小为3F2.如图1所示,用金属网把不带电的验电器罩起来,再使带电金属球靠近金属网,则下列说法正确的是A .箔片张开B .箔片不张开C .金属球带电电荷足够大时才会张开D .金属网罩内部电场强度为零3. 如图2所示的交流电路中,灯L 1、L 2和L 3均发光,如果保持交变电源两端电压的有效值不变,但频率减小,各灯的亮、暗变化情况为 A. 灯L 1、L 2均变亮,灯L 3变暗 B. 灯L 1、L 2、L 3均变暗C. 灯L 1不变,灯L 2变暗,灯L 3变亮D. 灯L 1不变,灯L 2变亮,灯L 3变暗4. 如图3所示的电路中,闭合开关S ,当滑动变阻器R 的滑片P 向上移动时,下列说法中正确的是 A.电流表示数变大 B.电压表示数变小 C.电阻R 0的电功率变大 D.电源的总功率变小5. 如图4所示,理想变压器原线圈匝数n 1=1100匝,副线圈匝数n 2=220匝,交流电源的电压u =2202sin100πt (V),电阻R =44Ω,电表均为理想交流电表。
则下列说法中正确的是 A.交流电的频率为50Hz B.电流表A 1的示数为0.20A C.变压器的输入功率为88W D.电压表的示数为44V6. 图5甲是洛伦兹力演示仪。
北京海淀区高三年级2016-2017学年度第一次综合练习数学试卷(理科)2017.3一、选择题:共8小题,每小题5分,共40分.在每小题列出的四个选项中,选出符合题目要求的一项. 1.已知集合(){}10A x x x =+≤,集合{}0B x x =>,则A B =( )A .{}1x x ≥-B .{}1x >-C .{}0x x ≥D .{}0x x >2.已知复数()()z i a bi a b R =+∈,),则“z 为纯虚数”的充分必要条件为( ) A .220a b +≠B .0ab =C .00a b =≠,D .00a b ≠=,3.执行如图所示的程序框图,输出的x 值为( ) A .0B .3C .6D .84.设a b R ∈,若a b >,则( ) A .11a b> B .22a b> C .lg lg a b >D .sin sin a b >5.已知1a xdx =⎰,12b x dx =⎰,0c =⎰,则a b c 、、的大小关系是( )A .a b c <<B .a c b <<C .b a c <<D .c a b <<6.已知曲线2:2x C y a ⎧=⎪⎪⎨⎪=+⎪⎩(t 为参数),()()1010A B -,、,,若曲线C 上存在点P 满足0AP BP ⋅=,则实数a 的取值范围为( )A.22⎡-⎢⎣⎦,B .[]11-,C.⎡⎣D .[]22-,7.甲、乙、丙、丁、戊五人排成一排,甲和乙都排在丙的同一侧,排法种数为( ) A .12B .40C .60D .808.某折叠餐桌的使用步骤如图所示,有如图检查项目:项目①:折叠状态下(如图1),检查四条桌腿长相等;项目②:打开过程中(如图2),检查''''OM ON O M O N ===; 项目③:打开过程中(如图2),检查''''OK OL O K O L ===; 项目④:打开后(如图3),检查123490∠=∠=∠=∠=; 项目⑤:打开后(如图3),检查''''AB A B C D CD ===.在检查项目的组合中,可以正确判断“桌子打开之后桌面与地面平行的是”( ) A .①②③ B .②③④C .②④⑤D .③④⑤二、填空题(每题5分,满分30分,将答案填在答题纸上)9.若等比数列{}n a 满足24548a a a a ==,,则公比q =________,前n 项和n S =________. 10.已知()()122020F F -,、,,满足122PF PF -=的动点P 的轨迹方程为________. 11.在ABC ∆中,cos c a B =.①A =________;②若1sin 3C =,则()cos B π+=________. 12.若非零向量a ,b 满足()0a a b ⋅+=,2a b =,则向量a ,b 夹角的大小为________.13.已知函数()210cos 0x x f x x x π⎧-≥=⎨<⎩,,,若关于x 的方程()0f x a +=在()0+∞,内有唯一实根,则实数a 的最小值是________.14.已知实数u v x y ,,,满足221u v +=,102202x y x y x +-≥⎧⎪-+≥⎨⎪≤⎩,则z ux vy =+的最大值是________.三、解答题(本大题共6小题,共80分.解答应写出文字说明、证明过程或演算步骤.) 15.(本小题满分13分)已知3π是函数()22cos sin 21f x x a x =++的一个零点. (Ⅰ)求实数a 的值;(Ⅱ)求()f x 的单调递增区间.据报道,巴基斯坦由中方投资运营的瓜达尔港目前已通航.这是一个可以停靠8~10万吨油轮的深水港,通过这一港口,中国船只能够更快到达中东和波斯湾地区,这相当于给中国平添了一条大动脉!在打造中巴经济走廊协议(简称协议)中,能源投资约340亿美元,公路投资约59亿美元,铁路投资约38亿美元,高架铁路投资约16亿美元,瓜达尔港投资约6.6亿美元,光纤通讯投资约为0.4亿美元.有消息称,瓜达尔港的月货物吞吐量将是目前天津、上海两港口月货物吞吐量之和.表格记录了2015年天津、上海两港口的月吞吐量(单位:百万吨):(Ⅰ)根据协议提供信息,用数据说明本次协议投资重点;(Ⅱ)从表中12个月任选一个月,求该月天津、上海两港口月吞吐量之和超过55百万吨的概率;(Ⅲ)将(Ⅱ)中的计算结果视为瓜达尔港每个月货物吞吐量超过55百万吨的概率,设X为瓜达尔未来12个月的月货物吞吐量超过55百万吨的个数,写出X的数学期望(不需要计算过程).如图,由直三棱柱111ABC A B C -和四棱锥11D BB C C -构成的几何体中,90BAC ∠=,1AB =,12BC BB ==,1C D CD ==1CC D ⊥平面11ACC A .(Ⅰ)求证:1AC DC ⊥;(Ⅱ)若M 为1DC 的中点,求证://AM 平面1DBB ;(Ⅲ)在线段BC 上是否存在点P ,使直线DP 与平面1BB D 所成的角为3π?若存在,求BPBC 的值,若不存在,说明理由.已知函数()()()2241ln 1f x x ax a x =-+-+,其中实数3a <. (Ⅰ)判断1x =是否为函数()f x 的极值点,并说明理由; (Ⅱ)若()0f x ≤在区间[]01,上恒成立,求a 的取值范围.已知椭圆22:12x G y +=,与x 轴不重合的直线l 经过左焦点1F ,且与椭圆G 相交于A B 、两点,弦AB 的中点为M ,直线OM 与椭圆G 相交于C D 、两点.(Ⅰ)若直线l 的斜率为1,求直线OM 的斜率; (Ⅱ)是否存在直线l ,使得2AM CM DM =⋅成立?若存在,求出直线l 的方程;若不存在,请说明理由.已知含有n 个元素的正整数集{}()12123n n A a a a a a a n =<<<≥,,,,具有性质P :对任意不大于()S A (其中()12n S A a a a =+++)的正整数k ,存在数集A 的一个子集,使得该子集所有元素的和等于k .(Ⅰ)写出12a a ,的值;(Ⅱ)证明:“12n a a a ,,,成等差数列”的充要条件是“()()12n n S A +=”; (Ⅲ)若()2017S A =,求当n 取最小值时n a 的最大值.2017年北京市海淀区高考数学一模试卷(理科)参考答案与试题解析一、选择题:本大题共8个小题,每小题5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.1.(5分)已知集合A={x|x(x+1)≤0},集合B={x|x>0},则A∪B=()A.{x|x≥﹣1} B.{x|x>﹣1} C.{x|x≥0} D.{x|x>0}【解答】解:∵集合A={x|x(x+1)≤0}={x|﹣1≤x≤0},集合B={x|x>0},∴A∪B={x|x≥﹣1}.故选:A.2.(5分)已知复数z=i(a+bi)(a,b∈R),则“z为纯虚数”的充分必要条件为()A.a2+b2≠0 B.ab=0 C.a=0,b≠0 D.a≠0,b=0【解答】解:复数z=i(a+bi)=ai﹣b(a,b∈R),则“z为纯虚数”的充分必要条件为﹣b=0,a≠0.故选:D.3.(5分)执行如图所示的程序框图,输出的x值为()A.0 B.3 C.6 D.8【解答】解:x=0,y=9,≠,x=1,y=8,≠,x=2,y=6,=4≠,x=3,y=3,3=,输出x=3,故选:B.4.(5分)设a,b∈R,若a>b,则()A.<B.2a>2b C.lga>lgb D.sina>sinb【解答】解:a,b∈R,a>b,当a>0,b<0时,A不成立,根据指数函数的单调性可知,B正确,根据对数函数的定义,可知真数必需大于零,故C不成立,由于正弦函数具有周期性和再某个区间上为单调函数,故不能比较,故D不成立,故选:B.5.(5分)已知a=xdx,b=x2dx,c=dx,则a,b,c的大小关系是()A.a<b<c B.a<c<b C.b<a<c D.c<a<b【解答】解:a=xdx=|=,b=x2dx=|=,c=dx=|=,则b<a<c,故选:C6.(5分)已知曲线C:(t为参数),A(﹣1,0),B(1,0),若曲线C上存在点P满足•=0,则实数a的取值范围为()A.,B.[﹣1,1] C.,D.[﹣2,2]【解答】解:∵A(﹣1,0),B(1,0),若曲线C上存在点P满足•=0,∴P的轨迹方程是x2+y2=1.曲线C:(t为参数),普通方程为x﹣y+a=0,由题意,圆心到直线的距离d=≤1,∴,故选C.7.(5分)甲、乙、丙、丁、戊五人排成一排,甲和乙都排在丙的同一侧,排法种数为()A.12 B.40 C.60 D.80【解答】解:根据题意,分2种情况讨论:①、甲和乙都排在丙的左侧,将甲乙安排在丙的左侧,考虑甲乙之间的顺序,有2种情况,排好后有4个空位,在4个空位中选一个安排丁,有4种情况,排好后有5个空位,在5个空位中选一个安排戊,有5种情况,则甲和乙都排在丙的左侧的情况有2×4×5=40种,②、甲和乙都排在丙的右侧,同理有40种不同的排法;故甲和乙都排在丙的同一侧的排法种数为40+40=80种;故选:D.8.(5分)某折叠餐桌的使用步骤如图所示,有如图检查项目:项目①:折叠状态下(如图1),检查四条桌腿长相等;项目②:打开过程中(如图2),检查OM=ON=O'M'=O'N';项目③:打开过程中(如图2),检查OK=OL=O'K'=O'L';项目④:打开后(如图3),检查∠1=∠2=∠3=∠4=90°;项目⑤:打开后(如图3),检查AB=A'B'=C'D'=CD.在检查项目的组合中,可以正确判断“桌子打开之后桌面与地面平行的是”()A.①②③B.②③④C.②④⑤D.③④⑤【解答】解:项目①:折叠状态下(如图1),四条桌腿长相等时,桌面与地面不一定平行;项目②:打开过程中(如图2),若OM=ON=O'M'=O'N',可以得到线线平行,从而得到面面平行;项目③:打开过程中(如图2),检查OK=OL=O'K'=O'L',可以得到线线平行,从而得到面面平行;项目④:打开后(如图3),检查∠1=∠2=∠3=∠4=90°,可以得到线线平行,从而得到面面平行项目⑤:打开后(如图3),检查AB=A'B'=C'D'=CD.桌面与地面不一定平行;故选:B.二、填空题(每题5分,满分30分,将答案填在答题纸上)9.(5分)若等比数列{a n}满足a2a4=a5,a4=8,则公比q=2,前n项和S n=2n﹣1.【解答】解:∵等比数列{a n}满足a2a4=a5,a4=8,∴,解得a1=1,q=2,∴前n项和S n==2n﹣1.故答案为:2,2n﹣1.10.(5分)已知F1(﹣2,0),F2(2,0),满足||PF1|﹣|PF2||=2的动点P的轨迹方程为.【解答】解:根据题意,F1(﹣2,0),F2(2,0),则|F1F2|=4,动点P满足||PF1|﹣|PF2||=2,即2<4,则P的轨迹是以F1、F2为焦点的双曲线,其中c=2,2a=2,即a=1,则b2=c2﹣a2=3,双曲线的方程为:;故答案为:.11.(5分)在△ABC中,c=acosB.①A=90°;②若sinC=,则cos(π+B)=﹣.【解答】解:①∵c=acosB.∴cosB==,整理可得:a2=b2+c2,∴A=90°;②∵sinC=,A=90°,∴B=90°﹣C,∴cos(π+B)=﹣cosB=﹣sinC=﹣故答案为:90°,.12.(5分)若非零向量,满足•(+)=0,2||=||,则向量,夹角的大小为120°.【解答】解:设向量,的夹角为θ,则θ∈[0°,180°];又•(+)=0,2||=||,∴+•=0,即+||×2||cosθ=0,解得cosθ=﹣,∴θ=120°,即向量,夹角为120°.故答案为:120°.13.(5分)已知函数f(x)=,,<若关于x的方程f(x+a)=0在(0,+∞)内有唯一实根,则实数a的最小值是﹣.【解答】解:作出f(x)的函数图象如图所示:∵f(x+a)在(0,+∞)上有唯一实根,∴f(x)在(a,+∞)上有唯一实根,∴﹣≤a<1.故答案为.14.(5分)已知实数u,v,x,y满足u2+v2=1,,则z=ux+vy的最大值是2.【解答】解:约束条件的可行域如图三角形区域:A(2,1),B(2,﹣1),C(0,1),u2+v2=1 设u=sinθ,v=cosθ,目标函数经过A时,z=2sinθ+2cosθ=2sin().目标函数经过B时,z=2sinθ﹣cosθ=(θ+β)(其中tanβ=).目标函数经过C时,z=sinθ≤1.所以目标函数的最大值为:2.故答案为:.三、解答题(本大题共6小题,共80分.解答应写出文字说明、证明过程或演算步骤.)15.(13分)已知是函数f(x)=2cos2x+asin2x+1的一个零点.(Ⅰ)求实数a的值;(Ⅱ)求f(x)的单调递增区间.【解答】解:(Ⅰ)由题意可知,即,即,解得.(Ⅱ)由(Ⅰ)可得==,函数y=sinx的递增区间为,,k∈Z.由<<,k∈Z,得<<,k∈Z,所以,f(x)的单调递增区间为,,k∈Z.16.(13分)据报道,巴基斯坦由中方投资运营的瓜达尔港目前已通航.这是一个可以停靠8~10万吨油轮的深水港,通过这一港口,中国船只能够更快到达中东和波斯湾地区,这相当于给中国平添了一条大动脉!在打造中巴经济走廊协议(简称协议)中,能源投资约340亿美元,公路投资约59亿美元,铁路投资约38亿美元,高架铁路投资约16亿美元,瓜达尔港投资约6.6亿美元,光纤通讯投资约为0.4亿美元.有消息称,瓜达尔港的月货物吞吐量将是目前天津、上海两港口月货物吞吐量之和.表格记录了2015年天津、上海两港口的月吞吐量(单位:百万吨):(Ⅰ)根据协议提供信息,用数据说明本次协议投资重点;(Ⅱ)从表中12个月任选一个月,求该月天津、上海两港口月吞吐量之和超过55百万吨的概率;(Ⅲ)将(Ⅱ)中的计算结果视为瓜达尔港每个月货物吞吐量超过55百万吨的概率,设X为瓜达尔未来12个月的月货物吞吐量超过55百万吨的个数,写出X的数学期望(不需要计算过程).【解答】解:(Ⅰ)本次协议的投资重点为能源,因为能源投资为340亿,占总投资460亿的50%以上,所占比重大.(Ⅱ)设事件A:从12个月中任选一个月,该月超过55百万吨.根据提供的数据信息,可以得到天津、上海两港口的月吞吐量之和分别是:56,49,58,54,54,57,59,58,58,56,54,56,其中超过55百万吨的月份有8个,所以,.(Ⅲ)X的数学期望EX=8.17.(13分)如图,由直三棱柱ABC﹣A1B1C1和四棱锥D﹣BB1C1C构成的几何体中,∠BAC=90°,AB=1,BC=BB1=2,C1D=CD=,平面CC1D⊥平面ACC1A1.(Ⅰ)求证:AC⊥DC1;(Ⅱ)若M为DC1的中点,求证:AM∥平面DBB1;(Ⅲ)在线段BC上是否存在点P,使直线DP与平面BB1D所成的角为?若存在,求的值,若不存在,说明理由.【解答】解:(Ⅰ)证明:在直三棱柱ABC﹣A1B1C1中,CC1⊥平面ABC,故AC⊥CC1,由平面CC1D⊥平面ACC1A1,且平面CC1D∩平面ACC1A1=CC1,所以AC⊥平面CC1D,又C1D⊂平面CC1D,所以AC⊥DC1.(Ⅱ)证明:在直三棱柱ABC﹣A1B1C1中,AA1⊥平面ABC,所以AA1⊥AB,AA1⊥AC,又∠BAC=90°,所以,如图建立空间直角坐标系A﹣xyz,依据已知条件可得A(0,0,0),,,,,,,B(0,0,1),B1(2,0,1),,,,所以,,,,,,设平面DBB1的法向量为,,,由即令y=1,则,x=0,于是,,,因为M为DC1中点,所以,,,所以,,,由,,,,,可得,所以AM与平面DBB1所成角为0,即AM∥平面DBB1.(Ⅲ)解:由(Ⅱ)可知平面BB1D的法向量为,,.设,λ∈[0,1],则,,,,,.若直线DP与平面DBB1成角为,则<,>,解得,,故不存在这样的点.18.(13分)已知函数f(x)=x2﹣2ax+4(a﹣1)ln(x+1),其中实数a<3.(Ⅰ)判断x=1是否为函数f(x)的极值点,并说明理由;(Ⅱ)若f(x)≤0在区间[0,1]上恒成立,求a的取值范围.【解答】解:(Ⅰ)由f(x)=x2﹣2ax+4(a﹣1)ln(x+1)可得函数f(x)定义域为(﹣1,+∞),=,令g(x)=x2+(1﹣a)x+(a﹣2),经验证g(1)=0,因为a<3,所以g(x)=0的判别式△=(1﹣a)2﹣4(a﹣2)=a2﹣6a+9=(a﹣3)2>0,由二次函数性质可得,1是函数g(x)的异号零点,所以1是f'(x)的异号零点,所以x=1是函数f(x)的极值点.(Ⅱ)已知f(0)=0,因为,又因为a<3,所以a﹣2<1,所以当a≤2时,在区间[0,1]上f'(x)<0,所以函数f(x)单调递减,所以有f(x)≤0恒成立;当2<a<3时,在区间[0,a﹣2]上f'(x)>0,所以函数f(x)单调递增,所以f(a﹣2)>f(0)=0,所以不等式不能恒成立;所以a≤2时,有f(x)≤0在区间[0,1]恒成立.19.(14分)已知椭圆G:+y2=1,与x轴不重合的直线l经过左焦点F1,且与椭圆G相交于A,B两点,弦AB的中点为M,直线OM与椭圆G相交于C,D两点.(1)若直线l的斜率为1,求直线OM的斜率;(2)是否存在直线l,使得|AM|2=|CM|•|DM|成立?若存在,求出直线l的方程;若不存在,请说明理由.【解答】解:(1)由已知可知F1(﹣1,0),又直线l的斜率为1,所以直线l的方程为y=x+1,设A(x1,y1),B(x2,y2),由解得或,所以AB中点,,于是直线OM的斜率为.(2)假设存在直线l,使得|AM|2=|CM|•|DM|成立.当直线l的斜率不存在时,AB的中点M(﹣1,0),所以,,矛盾;故直线的斜率存在,可设直线l的方程为y=k(x+1)(k≠0),联立椭圆G的方程,得(2k2+1)x2+4k2x+2(k2﹣1)=0,设A(x1,y1),B(x2,y2),则,,于是,点M的坐标为,,.直线CD的方程为,联立椭圆G的方程,得,设C(x0,y0),则,由题知,|AB|2=4|CM|•|DM|=4(|CO|+|OM|)(|CO|﹣|OM|)=4(|CO|2﹣|OM|2),即,化简,得,故,所以直线l的方程为,.20.(14分)已知含有n个元素的正整数集A={a1,a2,…,a n}(a1<a2<…<a n,n≥3)具有性质P:对任意不大于S(A)(其中S(A)=a1+a2+…+a n)的正整数k,存在数集A的一个子集,使得该子集所有元素的和等于k.(Ⅰ)写出a1,a2的值;(Ⅱ)证明:“a1,a2,…,a n成等差数列”的充要条件是“S(A)=”;(Ⅲ)若S(A)=2017,求当n取最小值时a n的最大值.【解答】解:(Ⅰ)由集合A={a1,a2,…,a n},}(a1<a2<…<a n,n≥3),由a n为正整数,则a1=1,a2=2.(Ⅱ)先证必要性:因为a1=1,a2=2,又a1,a2,…,a n成等差数列,故a n=n,所以;再证充分性:因为a1<a2<…<a n,a1,a2,…,a n为正整数数列,故有a1=1,a2=2,a3≥3,a4≥4,…,a n≥n,所以,又,故a m=m(m=1,2,…,n),故a1,a2,…,a n为等差数列.(Ⅲ)先证明(m=1,2,…,n).假设存在>,且p为最小的正整数.依题意p≥3,则a1+a2+…+a p﹣1≤1+2+…+2p﹣2=2p﹣1﹣1,又因为a1<a2<…<a n,故当k∈(2p﹣1﹣1,a p)时,k不能等于集合A的任何一个子集所有元素的和.故假设不成立,即(m=1,2,…,n)成立.因此,即2n≥2018,所以n≥11.因为S=2017,则a1+a2+…+a n﹣1=2017﹣a n,若2017﹣a n<a n﹣1时,则当k∈(2017﹣a n,a n)时,集合A中不可能存在若干不同元素的和为k,故2017﹣a n≥a n﹣1,即a n≤1009.此时可构造集合A={1,2,4,8,16,32,64,128,256,497,1009}.因为当k∈{2,2+1}时,k可以等于集合{1,2}中若干个元素的和;故当k∈{22,22+1,22+2,22+3}时,k可以等于集合{1,2,22}中若干不同元素的和;…故当k∈{28,28+1,28+2,…,28+255}时,k可以等于集合{1,2,…,28}中若干不同元素的和;故当k∈{497+3,497+4,…,497+511}时,k可以等于集合{1,2,…,28,497}中若干不同元素的和;故当k∈{1009,1009+1,1009+2,…,1009+1008}时,k可以等于集合{1,2,…,28,497,1009}中若干不同元素的和,所以集合A={1,2,4,8,16,32,64,128,256,497,1009}满足题设,所以当n取最小值11时,a n的最大值为1009.。
1D 1A 1B 1C F北京市海淀区2016-2017学年度第一学期高三期末理科数学2017.1一、选择题共8小题,每小题5分,共40分.在每小题列出的四个选项中,选出符合题目要求的一项. 1.抛物线22y x =的焦点到准线的距离为( ) A .12B .1 C.2D .32.在极坐标系中,点14π⎛⎫⎪⎝⎭,与点314π⎛⎫⎪⎝⎭,的距离为( ) A .1 B C D 3.右侧程序框图所示的算法来自于《九章算术》.若输入a 的值为16,b 的值为24则执行该程序框图输出的结果为( ) A .6 B .7 C .8D .94.已知向量,a b 满足2+=0a b ,()2+⋅=a b a ,则⋅=a b ( ) A .12-B .12C .2-D .2 5.已知直线l 经过双曲线2214x y -=的一个焦点且与其一条渐近线平行,则直线l 的方程可能是( ) A.12y x =-B .12y x =C .2y x =-D .2y x =-6.设x y ,满足0202x y x y x -≤⎧⎪+-≥⎨⎪≤⎩,则()221x y ++的最小值为( )A .1B .92C .5D .5 7.在手绘涂色本的某页上画有排成一列的6条未涂色的鱼,小明用红、蓝两种颜色给这些鱼涂色,每条鱼只能涂一种颜色,两条相邻的鱼不.都.涂.成红色...,涂色后,既有红色鱼又有蓝色鱼的涂色方法种数为( ) A .14 B .16 C .18 D .208.如图,已知正方体1111ABCD A BC D -的棱长为1,E F ,分别是棱11ADB C ,上的动点,设俯视图主视图1AE x B F y ==,.若棱1DD 与平面BEF 有公共点,则x y +的取值范围是( )A .[]01,B .1322⎡⎤⎢⎥⎣⎦,C .[]12,D .322⎡⎤⎢⎥⎣⎦二、填空题共6小题,每小题5分,共30分.9.已知复数z 满足()12i z +=,则z =_________.10.在621x x ⎛⎫+ ⎪⎝⎭的展开式中,常数项为_________.(用数字作答)11.若一个几何体由正方体挖去一部分得到,其三视图如图所示,则该几何体的体积为_________. 12.已知圆22:20C x x y -+=,则圆心坐标为_________;若直线l 过点()10-, 且与圆C 相切,则直线l 的方程为_________.13.已知函数()2sin 02y x πωϕωϕ⎛⎫=+>< ⎪⎝⎭,. ①若()01f =,则ϕ=_________;②若x R ∃∈,使()()24f x f x +-=成立,则ω的最小值是_________. 14.已知函数()||cos x f x e x π-=+,给出下列命题: ①()f x 的最大值为2;②()f x 在()1010-,内的零点之和为0; ③()f x 的任何一个极大值都大于1. 其中所有正确命题的序号是_________.三、解答题共6小题,共80分.解答应写出文字说明、演算步骤或证明过程. 15.(本小题满分13分)在ABC ∆中,2c a =,120B =,且ABC ∆. (Ⅰ)求b 的值; (Ⅱ)求tan A 的值.16.(本小题满分13分)诚信是立身之本,道德之基. 某校学生会创设了“诚信水站”,既便于学生用水,又推进诚信教育,并用“周实际回收水费周投入成本”表示每周“水站诚信度”. 为了便于数据分析,以四周为一周期......,下表为该水站连续十二周(共三个周期)的诚信度数据统计:(Ⅰ)计算表中十二周“水站诚信度”的平均数x ;(Ⅱ)分别从上表每个周期的4个数据中随机抽取1个数据,设随机变量X 表示取出的3个数据中“水站诚信度”超过91%的数据的个数,求随机变量X 的分布列和期望;(Ⅲ)已知学生会分别在第一个周期的第四周末和第二个周期的第四周末各举行了一次“以诚信为本”的主题教育活动.根据已有数据,说明两次主题教育活动的宣传效果,并根据已有数据陈述理由.17.(本小题满分14分)如图1,在梯形ABCD 中,//AB CD ,90ABC ∠=,224AB CD BC ===,O 是边AB 的中点.将三角形AOD 绕边OD 所在直线旋转到1AOD 位置,使得1120AOB ∠=;如图2,设m 为平面1A DC 与平面1AOB 的交线. (Ⅰ)判断直线DC 与直线m 的位置关系并证明;(Ⅱ)若直线m 上的点G 满足1OG A D ⊥,求出1AG 的长; (Ⅲ)求直线1AO 与平面1A BD 所成角的正弦值.18.(本小题满分13分)已知()()0231A B , ,, 是椭圆()2222:10x y G a b a b+=>>上的两点.AOBCD1图ODCB2图1A(Ⅰ)求椭圆G 的离心率;(Ⅱ)已知直线l 过点B ,且与椭圆G 交于另一点C (不同于点A ),若以BC 为直径的圆经过点A ,求直线l 的方程.19.(本小题满分14分)已知函数()ln 1af x x x=--. (Ⅰ)若曲线()y f x =存在斜率为1-的切线,求实数a 的取值范围;(Ⅱ)求()f x 的单调区间; (Ⅲ)设函数()ln x ag x x+=,求证:当10a -<<时,()g x 在()1+∞,上存在极小值.20.(本小题满分13分)对于无穷数列{}n a 、{}n b ,若{}{}()1212max min k k k b a a a a a a k N *=-∈,,,,,,,则称{}n b 是{}n a 的“收缩数列”. 其中,{}12max k a a a ,,,,{}12min k a a a ,,,分别表示12k a a a ,,,中的最大数和最小数.已知{}n a 为无穷数列,其前n 项和为n S ,数列{}n b 是{}n a 的“收缩数列”. (Ⅰ)若21n a n =+,求{}n b 的前n 项和; (Ⅱ)证明:{}n b 的“收缩数列”仍是{}n b ; (Ⅲ)若()()1211122n n n n n n S S S a b +-+++=+()n N *∈,求所有满足该条件的{}n a .海淀区高三年级第一学期期末练习数学(文科)答案及评分标准 2017.1一、选择题共8小题,每小题5分,共40分。
2016-2017 北京海淀区高三英语期末试卷第二部分:知识运用第一节:单项填空21. Things don’t always go as planned, ____ I still stay positive.A. orB. asC. butD. for22. --- What a drive! I’m tired out.--- No wonder! You have been driving for such a long time ____ taking a break.A. byB. withoutC. throughD. in23. The 24 solar terms (二十四节气) ____ a great effect on Chinese people’s lives for thousands of years.A. have hadB. hadC. haveD. had had24. ____ as a volunteer teacher in Tibet for a year, Linda has become more experienced.A. To workB. WorkingC. Having workedD. Worked25. Yesterday, I went back to my primary school, ____ my teachers and I recalled our good old days.A. whichB. thatC. whenD. where26. Li Hua’s parents hold different opinions on whether they should have ____ child.A. anotherB. otherC. othersD. the other27. Social media, like WeChat, ____ the way of communication nowadays.A. are changingB. changeC. changedD. were changing28. In big cities, young people often go to café ____ with friends.A. relaxedB. relaxC. to relaxD. relaxing29. I usually sleep with window open ____ it is really cold.A. ifB. unlessC. now thatD. in case30. Beijing’s new international airport ____ into use in 2019, according to the spokesperson.A. was putB. will putC. has putD. will be put31. I had to catch my flight. That was ____ I left Tom’s party so early yesterday.A. whatB. howC. whyD. when32. Jenny was practicing her speech in the hall when she heard her name_____.A. callingB. calledC. to callD. having called33. If you want to be on the school football team, you ____train harder.A. canB. wouldC. mightD. must34. A long road tests a horse’s strength and a long team task ____ a man’s heart.A. provesB. will proveC. is provingD. has proved35. If there were no cellphones, life ____ quite different because we depend too much on them.A. will beB. would beC. isD. were第二节:完形填空I was the fool at s chool, regarded as a special needs student. I was termed as such. Obviously, because I was not interestedin school and did not care for my __36__.Over time, I started to believe in my stupidity. I __37__ the fact that I was in special needs classes and poured it out as anger and depression. But one activity __38__ this view of myself: chess.I started to play chess with my father after school simply because I wanted to __39__ him at something. My father wasa __40__ man, fond of physics, writing, religion… almost every __41__. He was called a walking dictionary. So, winning inchess against my father would be a __42__ that I had intellectual power. On the small chessboard, I had chance to __43__my so-called inability.Game after game, I wanted to beat my father even more. I started to study chess books and play against a chess computerto __44__ my skills. One weekend, I finally checkmated (将杀) my father on a ferry ride, which made me feel __45__.Two years later, I became the second board on my school chess team, with our top board being the best high school player in the state. But before the tournament season, our top player __46__ to come. There came my chance to play as top board against the best player in other states.I was determined to show who I had become: a(n) __47__ person able to win with calculation, logic and will. My most__48__ game came in the final round. Our team was facing a high school which only excellent students attended. It was__49__ a match between a special needs student and a smart soul. My opponent (对手) was playing well and kept __50__ while I kept defending to keep my king safe. He spent long trying to breakdown my defenses, but could not find the final push. I __51__ with more defensive moves, trying to make it as difficult for him as possible. With little __52__ left, he startedto make rapid moves. __53__ he could make the final decision, he ran out of time. Honestly, as his clock flag fell, I jumpedup out of my seat and kissed the floor out of excitement. Of course it was not the most sportsmen-like __54__, but I could not control my emotions.While holding my winner’s cup, I knew I was not __55__. The inferiority complex (自卑感) had melted away, and I realized that underneath our thoughts, each person is a genius.36. A. habits B. grades C. plans D. benefits37. A. noticed B. explained C. accepted D. ignored38. A. changed B. supported C. questioned D. showed39. A. please B. comfort C. beat D. disturb40. A. smart B. strict C. quiet D. strong41. A. method B. topic C. event D. field42. A. dream B. lesson C. theory D. sign43. A. prove B. expose C. overcome D. promote44. A. teach B. sharpen C. choose D. invent45. A. overjoyed B. disappointed C. puzzled D. interested46. A. promised B. managed C. happened D. failed47. A. brave B. lucky C. active D. intelligent48. A. terrible B. memorable C. dangerous D. popular49. A. normally B. possibly C. actually D. partly50. A. attacking B. smiling C. pausing D. escaping51. A. returned B. quit C. won D. exchanged52. A. patience B. time C. energy D. wisdom53. A. Once B. Until C. Before D. Unless54. A. spirit B. thought C. comment D. behavior55. A. proud B. stupid C. bright D. lazy第三部分:阅读理解第一节:阅读下列短文,从每题所给的A、B、C、D 四个选项中,选出最佳答案。
海淀区高三年级第一学期期末练习数学(理科)第一部分(选择题 共40分)一、选择题共8小题,每小题5分,共40分。
在每小题列出的四个选项中,选出符合题目要求的一项。
(1)复数12ii+= A. 2i - B. 2i + C. 2i -- D. 2i -+ (2)在极坐标系中Ox ,方程2sin ρθ=表示的圆为A. B. C. D.(3)执行如图所示的程序框图,输出的k 值为 A.4 B.5 C.6 D.7(4)设m 是不为零的实数,则“0m f ”是“方程221x y m m-=表示 的曲线为双曲线”的A.充分不必要条件B.必要不充分条件C.充分必要条件D.既不充分也不必要条件(5)已知直线0x y m -+=与圆22:1O x y +=相交于,A B 两点,且AOB ∆为正三角形,则实数m 的值为A. 3B. 6C. 3或3-D.6或6-(6)从编号分别为1,2,3,4,5,6的六个大小完全相同的小球中,随机取出三个小球,则恰有两个小球编号相邻的概率为 A. 15 B. 25 C. 35 D. 45(7)某三棱锥的三视图如图所示,则下列说法中: ①三棱锥的体积为16②三棱锥的四个面全是直角三角形 ③三棱锥的四个面的面积最大的是3所有正确的说法是A. ①B. ①②C. ②③D. ①③(8)已知点F 为抛物线2:2(0)C y px p =f 的焦点,点K 为点F 关于原点的对称点,点M在抛物线C 上,则下列说法错误..的是 A.使得MFK ∆为等腰三角形的点M 有且仅有4个 B.使得MFK ∆为直角三角形的点M 有且仅有4个 C. 使得4MKF π∠=的点M 有且仅有4个 D. 使得6MKF π∠=的点M 有且仅有4个第二部分(非选择题 共110分)二、填空题共6小题,每小题5分,共30分。
(9)点(2,0)到双曲线2214x y -=的渐近线的距离是 . (10)已知公差为1的等差数列{}n a 中,1a ,2a ,4a 成等比数列,则{}n a 的前100项和为 .(11)设抛物线2:4C y x =的顶点为O ,经过抛物线C 的焦点且垂直于x 轴的直线和抛物线C 交于,A B 两点,则OA OB +=u u u r u u u r.(12)已知(51)nx -的展开式中,各项系数的和与各项二项式系数的和之比为64:1,则n = .(13)已知正方体1111ABCD A B C D -的棱长为M 是棱BC 的中点,点P 在底面ABCD 内,点Q 在线段11A C 上,若1PM =,则PQ 长度的最小值为 .(14)对任意实数k ,定义集合20(,)20,0k x y D x y x y x y R kx y ⎧⎫-+≥⎧⎪⎪⎪=+-≤∈⎨⎨⎬⎪⎪⎪-≤⎩⎩⎭. ①若集合k D 表示的平面区域是一个三角形,则实数k 的取值范围是 ; ②当0k =时,若对任意的(,)k x y D ∈,有(3)1y a x ≥+-恒成立,且存在(,)k x y D ∈,使得x y a -≤成立,则实数a 的取值范围为 .三、解答题共6小题,共80分。
海淀区高三年级第一学期期末练习
数学(理科)2017.1
本试卷共4页,150分。
考试时长120分钟。
考生务必将答案答在答题卡上,在试卷上 作答无效。
考试结束后,将本试卷和答题卡一并交回。
一、选择题共8小题,每小题5分,共40分。
在每小题列出的四个选项中,选出符合题目
要求的一项。
1. 抛物线22y x =的焦点到准线的距离为
A.
1
2
B.1
C.2
D.3 2. 在极坐标系中,点π1,4⎛⎫
⎪⎝⎭
与点3π1,4⎛⎫ ⎪⎝⎭的距离为
A.1
B.
C.
3.右侧程序框图所示的算法来自于《九章算术》.若输入a 的
值为16,b 的值为24,则执行该程序框图输出的结果为 A. 6 B. 7 C. 8 D. 9
4. 已知向量,a b 满足2+=0a b ,()2+⋅=a b a ,则⋅=a b
A.12-
B.1
2
C.2-
D.2
5.已知直线l 经过双曲线2
214
x y -=的一个焦点且与其一条渐近线平行,则直线l 的方程可能
是
A.12y x =-
B.1
2
y x =
C.2y x =-
D.2y x =-6.设,x y 满足0,
20,2,x y x y x -≤⎧⎪
+-≥⎨⎪≤⎩
则()221x y ++的最小值为
A.1
B.9
2
C. 5
D. 9
7.在手绘涂色本的某页上画有排成一列的6条未涂色的鱼,小明用红、蓝两种颜色给这些鱼涂色,每条鱼只能涂一种颜色,两条相邻的鱼不.都.涂.成红色...,涂色后,既有红色鱼又有蓝色鱼的涂色方法种数为 A.14B.16C. 18D. 20
8.如图,已知正方体1111ABCD A B C D -的棱长为1,,E F 分别是棱11,AD B C 上的动点,设1,AE x B F y ==.若棱.1DD 与平面
BEF 有公共点,则x y +的取值范围是 A.[0,1]B.13[,]22C.[1,2]D.3[,2]2
二、填空题共6小题,每小题5分,共30分。
9.已知复数z 满足(1i)2z +=,则z =____.
10.在261
()x x
+的展开式中,常数项为____.(用数字作答)
11.若一个几何体由正方体挖去一部分得到,其三视图如图所示,则该几何体的体积为.
12.已知圆C :2220x x y -+=,则圆心坐标为____; 若直线l 过点(1,0)-且与圆C 相切,则直线l 的方程为____.
13.已知函数2sin()y x ωϕ=+π
(0,||)2
ωϕ><.
①若(0)1f =,则ϕ=___;
②若x ∃∈R ,使(2)()4f x f x +-=成立,则ω的最小值是____.
14.已知函数||()e cos πx f x x -=+,给出下列命题: ①()f x 的最大值为2;
②()f x 在(10,10)-内的零点之和为0; ③()f x 的任何一个极大值都大于1. 其中所有正确命题的序号是___.
三、解答题共6小题,共80分。
解答应写出文字说明、演算步骤或证明过程。
俯视图
主视图A
B
C
D
1
D 1
A 1
B 1
C E F
15.(本小题满分13分)
在∆ABC 中,2c a =,120B = ,且∆ABC
(Ⅰ)求b 的值; (Ⅱ)求tan A 的值.
16. (本小题满分13分)
诚信是立身之本,道德之基.某校学生会创设了“诚信水站”,既便于学生用水,又推进
诚信教育,并用“周实际回收水费
周投入成本”表示每周“水站诚信度”. 为了便于数据分析,以四周为一....周期
,下表为该水站连续十二周(共三个周期)的诚信度数据统计: (Ⅰ)计算表中十二周“水站诚信度”的平均数x ;
(Ⅱ)分别从上表每个周期的4个数据中随机抽取1个数据,设随机变量X 表示取出的3
个数据中“水站诚信度”超过91%的数据的个数,求随机变量X 的分布列和期望; (Ⅲ)已知学生会分别在第一个周期的第四周末和第二个周期的第四周末各举行了一次
“以
诚信为本”的主题教育活动.根据已有数据,说明两次主题教育活动的宣传效果,并根据已有数据陈述理由.
17. (本小题满分14分)
如图1,在梯形ABCD 中,//AB CD ,90ABC ∠= ,224AB CD BC ===,O 是边AB 的中点. 将三角形AOD 绕边OD 所在直线旋转到1A OD 位置,使得1
120AOB ∠= ,如图2.设m 为平面1A DC 与平面1A OB 的交线.
(Ⅰ)判断直线DC 与直线m 的位置关系并证明;
(Ⅱ)若直线m 上的点G 满足1OG A D ⊥,求出1A G 的长;4
(Ⅲ)求直线1A O 与平面1A BD 所成角的正弦值
18. (本小题满分13分)
A
O
B
C D
1
图O D
C
B
2
图1
A
已知(0,2),(3,1)A B 是椭圆G :22
221(0)x y a b a b
+=>>上的两点.
(Ⅰ)求椭圆G 的离心率;
(Ⅱ)已知直线l 过点B ,且与椭圆G 交于另一点C (不同于点A ),若以BC 为直径的圆
经过点A ,求直线l 的方程.
19. (本小题满分14分)
已知函数()ln 1a f x x x
=--. (Ⅰ)若曲线()y f x =存在斜率为1-的切线,求实数a 的取值范围; (Ⅱ)求()f x 的单调区间;
(Ⅲ)设函数()ln x a
g x x
+=,求证:当10a -<<时,()g x 在(1,)+∞上存在极小值.
20. (本小题满分13分)
对于无穷数列{}n a ,{}n b ,若1212max{,,,}min{,,,}(1,2,3,)k k k b a a a a a a k =-= ,则称{}n b 是{}n a 的“收缩数列”.其中,12max{,,,}k a a a ,12min{,,,}k a a a 分别表示12,,,k
a a a 中的最大数和最小数.
已知{}n a 为无穷数列,其前n 项和为n S ,数列{}n b 是{}n a 的“收缩数列”. (Ⅰ)若21n a n =+,求{}n b 的前n 项和; (Ⅱ)证明:{}n b 的“收缩数列”仍是{}n b ; (Ⅲ)若121(1)(1)
22
n n n n n n S S S a b +-+++=
+ (1,2,3,)n = ,求所有满足该条件的{}n a .。