2018届湖南省长沙市长郡中学高三第四次月考数学(理)试题 Word版 含答案

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湖南省长沙长郡中学2015届高三上学期第四次月考英语试题 Word版含答案

湖南省长沙长郡中学2015届高三上学期第四次月考英语试题 Word版含答案

湖南省长沙长郡中学2015届高三上学期第四次月考英语试题(word版)本试卷分为四个部分,包括听力、语言知识运用、阅读和书面表达。

时量1 20分钟。

满分1 50Part I Listening Comprehension (30 marks)Section A (22.5 marks)Directions In this section ,you will hear six conversations between two speakers.For each conversation , there are.several questions and each question is followed by three choices marked A ,B and C.Listen carefully and then choose the best answer for each question.You will hear each conversation TWICE.Conversation 11.Who used the car this morning?A.The son.B.The aunt.C.The mother.2.Where are the keys found?A.In the purse.B.In the pocket.C.In the drawer.Conversation 23.Which of the following is TRUE about the man?A.He borrowed some money.B.He is caught in the traffic.C.He will meet his teacher.4.How is the man going home?A.By train.B.By bus.C.By taxi.Conversation 35.When was the party held?A.In the morning.B.In the afternoon.C.In the evening.6.Why didn't the woman go to the party?A.She didn't feel well.B.She didn't have the time.C.She didn't get an invitation.Conversation 47.What does the man want to buy?A.A camera.B.A mobile phone.C.A music player.8.Which of the following does the man choose?A.The PE310.B.The RT230.C.The FG160.9.How much does the man pay?A.$300.B.$270.C.$100.Conversation 510.What is the woman?A.A dress designer.B.A basketball player.C.A headmaster.11.What do we know about the man s travel plan?A.He's going by air.B.He's leaving for Paris.C.He's arriving this afternoon.12.Who is going to pick up the man?A.The woman's son.B.The woman's brother.C.The woman herself.Conversation 613.What is the man doing now?A.Looking for a job.B.Studying in a university.C.Teaching at a high school.14.What kind of movie does the man like best?A.Adventure.B.Comedy.C.Drama.15.Where are the speakers going first?A.The supermarket.B.The cinema.C.The cafe.Section B (7.5 marks)Directions In this section @ you will hear a short passage.Listen carefully and then fill in the numbered blanks with the information you've got.Fill in each blank with NO MORE TH.ANTHREE WORDS.You will hear the short passage.TWICE.Essav competition introductionPart ⅡLanguage Knowledge (45 marks)Section A (15 marks)Directions Beneath each of the following sentences there, are four choices marked A,B,C and.D.Choose the one that best completes the sentence.21.It was never clear _____ the man hadn't reported the accident sooner.A.that B.what C.when D.why 22.After the fierce competition, the students were taken to their camp, _____ they would rest for next round.A.where B.who C.which D.what 23.To learn English well, we should find opportunities to hear English as much as we can.A.speak B.speaking C.spoken D.to speak24.—Why.Jack, you look so tired!—Well.I the house and I must finish the work tomorrow.A.was painting B.will be paintingC.have painted D.have been painting25.So sudden_____ that the enemy had no time to escape.A.did the attack B.the attack didC.was the attack D.the attack was26.It's not the score you've got, but the attitude you choose ______ determines our evaluation of your work.A.which B.that C.what D.who27.All we are required to do ______ record a "weike" where we explain what we think students are puzzled about.A.are B.is C.was D.were28.Our school called on us to donate our pocket money to the school damaged by the flood, _____ the students to return to their classrooms.A.enabling B.having enabled C.enable D.to have enabled 29.—I prefer shutting myself in and listening to music all day on Sundays.—That's_____I don't agree.You should have a more active life.A.where B.how C.when D.what30.John thinks it won't be long _____ he is ready for his new job.A.when B.after C.before D.since31._____ an important decision more on emotion than on reason, you will regret it sooner or later.A.Based B.Basing C.Base D.To base 32.The manager is said to have arrived back from Paris where he ______ some European partners.A.would meet B.is meeting C.meets D.had met33._____ something to drink, as the movie will last three hours.A.Grab B.To grab C.Grabbing D.Grabbed 34.The president hopes that the people will be better off when he quits than when he _____.A.has started B.starts C.started D.will start35.—I left my handbag on the train, but luckily someone gave it to a railway official.—How unbelievable to get it back! I mean.someone _____ it.A.will have stolen B.might have stolenC.should have stolen D.must have stolenSection B (18 marks)Directions For each blank in the following passage there, are.four words or phrases marked A, B, C and D.Fill in each blank with the word or phrase that best fits the context.Michael Greenberg is a very popular New Yorker.He is not famous in sports or the arts.But people in the streets know about him, especially those who are 36For those people, he is "Gloves" Greenberg.How did he get that name? He looks like any other businessman, wearing a suit and carrying a briefcase (公文箱).But he's 37 His briefcase always has some gloves.In winter, Mr.Greenberg does not 38 like other New Yorkers.who look at the sidewalk and 39 the street.He looks around at people.He stops when he sees someone with no gloves.He gives them a pair and then he 40 , looking for more people with cold hands.On winter days.Mr.Greenberg gives away gloves.During the rest of the year, he 41 gloves.People who have heard about him 42 him gloves, and he has many in his apartment.Mr.Greenberg began doing this 21 years ago.Now.many poor New Yorkers know him and 43 his behavior.But people who don't know him are sometimes 44 him.They don't realize that he just wants to make them 45 .It runs in the 46 Michael's father always helped the poor as he believed it made everyone happier.Michael Greenberg feels the same.A pair of gloves may be a 47 thing.but it can make a big difference in winter.36.A.old B.busy C.kind D.poor 37.A.calm B.different C.crazy D.curious 38.A.act B.Sound C.feel D.dress 39.A.cross over B.drive along C.hurry down D.keep off 40.A.holds up B.hangs out C.moves on D.turns around 41.A.borrows B.sells C.returns D.buys 42.A.call B.send C.lend D.show 43.A.understand B.dislike C.study D.excuse 44.A.sorry for B.satisfied with C.proud of D.surprised by 45.A.smart B.rich C.special D.happy 46.A.city B.family C.neighborhood D.company 47.A.small B.useful C.delightful D.comforting Section C (12 marks)Directions Complete the following passage by filling in each blank with one word.that best fits the context.One day the employees of a large company returned from their lunch and were greeted with a sign on the front door.48 sign said "Yesterday the person who has been limiting your growth in this company passed 49 .We invite you to join the funeral in the room that has been prepared in the gym."At first everyone was sad to hear 50 one of their colleagues had died.but after a while they started getting curious 51 who this person might be.The excitement grew 52 the employees arrived at the gym to pay their last respect.Everyone wondered "Who is this person that was limiting my progress? Well.at least he is no longer here."One by one the employees got closer to the coffin(棺材)53 when they look inside it they suddenly became speechless.There was a mirror inside the coffin everyone 54 looked inside it could see himself.There was also a sign next to the mirror that said "There is only one person who is capable to set limits to your growth it is 55 "Part m Reading Comprehension (30 marks)Directions Read the following three passages.Each passage is followed by several questions or unfinished statements.For each of them there, are four choices marked A,B,C and D.Choose the.one that fits best according to the information given in the.passage.AJerry was a unique manager because he had several waiters who had followed him around from restaurant to restaurant.The reason the waiters followed Jerry was because of his attitude.He was a natural motivator.It an employee was having a bad day.Jerry was there telling the employee how to look on the positive side of the situation.Seeing this style really made me curious, so one day I went up to Jerry and asked him, "I don't get it! You can't be a positive person all of the time.How do you do it?" Jerry replied, "Each morning I wake up and say to myself, "Jerry, you have two choices today.You can choose to be in a good mood or you can choose to be in a bad mood.' I choose to be in a good mood.Each time something bad happens, I can choose to be a victim or I can choose to learn from it.I choose to learn from it.Every time someone comes to me complaining.I can choose to accept their complaining or I can point out the positive side of life.I choose the positive side of life.The bottom line It's your choice how you live life." I reflected on what Jerry said.Later.I left the restaurant industry to start my own business.We lost touch, but I often thought about him when I made a choice about life.Several years later.I heard that Jerry did something you are never supposed to do in a restaurant business he left the back door open one morning and was held up at gun point by three armed robbers.While trying to open the safe, he forgot thepassword, nervous.The robbers panicked and shot him.Luckily, Jerry was found relatively quickly and rushed to the local hospital.After 18 hours of surgery and weeks of intensive care.Jerry was released from the hospital with fragments(碎片)of the bullets still in his body.I saw Jerry about six months after the accident.When I asked him how he was.he replied."The first thing that went through my mind was that I should have locked the back door," Jerry replied."Then, as I lay on the floor.I remembered that I had two choices I could choose to live.or I could choose to die.I chose to live." " Weren ' t you scared? Did you lose consciousness?" I asked.Jerry continued, "The doctors and nurses were great.They kept telling me I was going to be fine.But when they wheeled me into the emergency room and I saw the expressions on the faces of the doctors and nurses, I got really scared.I knew I needed to take action.""What did you do?" I asked."Well, there was a big.strong nurse shouting questions at me." said Jerry."She asked if I was allergic (过敏的)to anything."Yes.' I replied.The doctors and nurses stopped working as they waited for my reply.I took a deep breath and yelled, "Bullets!' Over their laughter, I told them."I am choosing to live.Operate on me as if I am alive, not dead.'"Jerry lived thanks to the skill of his doctors, but also because of his amazing attitude.I learned from him that every day we have the choice to live fully.56.The author left Jerry's restaurant because he_____.A.wanted to start business on his ownB.was afraid of another robbery laterC.was not equal to the job any longerD.didn't get along well with others57.Why was Jerry shot?A.Because he left the back door open.B.Because he opened the safe too slowly.C.Because he pretended to forget the password.D.Because he didn't open the safe in time.58.What was Jerry really afraid in the emergency room?A.The doctors and nurses refused to save him.B.He decided to take action to live again.C.The doctors and nurses came with expressions of regret at his being shotD.He might not be saved by doctors and nurses.59.From the passage we can learn that Jerry _____.A.was no longer positive to his life after the operationB.was optimistic even when things were at their worstC.influenced all his colleagues in many waysD.was badly injured and stayed in hospital for six months60.Which of the following is conveyed in this article?A.Where there is life.there is hope.B.Everything comes to him who waits.C.Humor is the best medicine that creates miracle.D.Attitude determines everything.BAn old problem is getting new attention in the United State s—bullying.Recent cases included the tragic case of a fifteen-year-old girl whose family moved from Ireland.She hanged herself in Massachusetts in January following months of bullying.Her parents criticized her school for failing to protect her.Officials have brought criminal charges against severalteenagers.Judy Kaczynski is president of an anti-bullying group called Bully Police USA.Her daughter Tina was the victim of severe bullying starting in middle school in the state of Minnesota.She said, "Our daughter was a very outgoing child.She was a bubbly personality, very involved in all kinds of things, had lots of friends.And over a period of time her grades fell completely.She started having health issues.She couldn't sleep.She wasn't eating.She had terrible stomach pains.She started clenching (紧握,紧咬)her jaw and grinding her teeth at night.She didn't want to go to school."Bullying is defined as negative behavior repeated over time against the same person.It can involve physical violence.Or it can be verba l—for example, insults or threats.Spreading lies about someone or excluding a person from a group is known as social or relational bullying.And now there is cyberbullying, which uses the Internet, e-mail or text messages.It has easy appeal for the bully because it does not involve face-to-face contact and it can be done at any time.The first serious research studies into bullying were done in Norway in the late 1970s.The latest government study in the United States was released last year.It found that about one-third of students aged twelve to eighteen were bullied at school.Susan Sweater is a psychologist at the University of Nebraska-Lincoln and co-director of the Bullying Research Network.She says schools should treat bullying as a mental health problem to get bullies and victims the help they need.She says bullying is connected to depression, anxiety and anti-social behavior, and bullies are often victims themselves.61.From the case of Tina, we can know that _____.A.bullying is rare B.victims suffered a lotC.schools are to blame D.personalities are related62.Which of the following is NOT bullying?A.To beat someone repeatedly.B.To call someone names.C.To isolate someone from friends.D.To refuse to help someone in need.63.Why is cyberbullying appealing to the bully?A.Because it can involve more people.B.Because it can create worse effects.C.Because it is more convenient.D.Because it can avoid cheating.64.According to Susan Sweater._____.A.bullies are anti-socialB.bullies should give victims helpC.students are not equally treatedD.bullies themselves also need help65.Which of the following can be the best title of the text?A.Bullyin g—An Irish Girl Committed SuicideB.15-year-old Irish Girl Committed SuicideC.Cyberbullyin g—Taking Off in SchoolsD.How to Find Bullying among TeensC"The days when the management in Western companies presented gold watches to long-serving employees to thank them for loyal service is now just a memory." says the Educational and Training Support Agency.This new development in the shape and movement of the workforce throughout Western businesses is partly a result of the way that layers of middle management are being removed, leaving more workers responsible for their own development."Having workers take responsibility for their own development might be dramatic, but it is now the rule," says the Educational and Training Support Agency."Today, not only are workers more mobile, they have to run to keep up with changes." says the Government-founded agency."It is no longer enough for a worker to gain a set of skills.Workers need the ability to react and get used to changes." This new system is also being pushed along by the way that industry is looking to its workers to renew their own skills.In the United States, some companies have contracts (合同)which repair their employees to show regularly how they have their skills up to date.Contrary to this traditions of the past, employers in the West are now looking for autonomous learners as recruits, people who can develop their own continuing education beyond the school and university system.At the same time.businesses are developing the capacity for workers to take up autonomous learning on site in workplace, so that the skills and abilities of all workers in a business continue to improve and increase."This.of course," says business theory."will also improve the productivity (生产率)of the workers and therefore the profits of the company."66.The management in western companies no longer presents gold watches to their employees because _____.A.they are not loyal to companiesB.other rewards replace gold watchesC.the way prove to be a failureD.serving a company for life is rare now67.The western workforce frequently changes their jobs partly because _____.A.hopping from job to job has become a new trendB.employees are expecting to have more experiences in their lifeC.workers have to take more responsibility for themselvesD.it is easy to complete themselves by doing so68.The passage seems to suggest that the present situation in society requires that workers shouldA.show more loyalty to their companiesB.try to develop their skills to fit in with changesC.go to college to have their skills up to dateD.be quick in changing their careers if there is the possibility69.The phrase "autonomous learner" in the last paragraph means _____.A.people who have received higher educationB.people who study hard themselvesC.people who learn things very quicklyD.people who continue their study beyond regular education70.Companies require their employee's development mainly because _____.A.it will finally help to bring more profits to the companyB.it can attract more workers who pay special attention to self-developmentC.it is good for the employees to develop their skillsD.it will make workers more responsible and loyal to the companyPart Iv Writing (45 marks)Section A (10 marks)Directions Read.the following passage.Fill.in the numbered, blanks by using the information from the passage.Write NO MORE THAN THREE WORDS for each answer.Learning to improve your focus throughout the day can be a little difficult, only because we are talking about 18 to 24 hours, depending on the number of hours you sleep.However, if we break down your day into manageable time frames, it would make it much easier to learn to improve your focus.Focus, or concentration, is a skill that can be taught, so there are some exercises you can do to improve your focus.Start with easy exercises like staring at a picture on the wall for a few minutes without moving or talking to anyone.Once you learn how to block out your surroundings, your focus will improve.Other mind exercises you can do are internalizing.This is when you picture yourself in a desired situation, and then you work around your picture.Actors do this a lot to block out laughter, noise, or other distractions.An example of this would be to imagine you in a potentially stressful situation, like a singer in a concert.Try to play out the scene in your mind what you would do if different scenarios were to happen.This can actually be a lot of fun.and you learn how to improve your focus by concentrating on one thing only.If this sounds a little strange to you, you could try another strategy.Why not make lists? Make a list for the things you need to accomplish for the morning, another for the afternoon.and finally, another list for the evening.Study your lists carefully and see where you can move things around.For instance, if you have a dinner to arrange that evening, don't bunch up everything in the afternoon, right before the guests arrive.Divide your chores and errands between morning and afternoon, and give yourself an hour or two to relax before the guests arrive.Planning helps you focus.It will also not stress you out.Another way to improve your focus is to take breaks.If children have rest and lunch as their breaks, adults should also allow themselves the privilege of stopping for a drink or a 30 minute sitcom on TV.Of course, if you are working in an office, you are allowed coffee breaks.Use this time wisely.Don't spend it with your co-workers beside the coffee machine talking about problems in the office.Doing this would actually stress you and get you to lose focus on the things that need to be done.Your breaks should be as quiet as possible.Read a book.take a walk.or visit a daycare.Go and do anything that will give your brain a rest.The reason why we lose focus so easily is because we have too much on our minds.Of course, it could also be because you are bored with nothing to do all day.A good balance between a too relaxed brain and an overly active brain is a desirable situation to be in.Find your capacity to work, and try not to veer away too far from it on a daily basis.Improving your focusalso means knowing what you can do and being confident about doing it well.Focus is important but difficult to improve1.71 to improve your focusI .Staring at picture.◆Staring at a wall picture 72 to learn to block out surroundingsⅡ.73 .◆Concentrating on imagining a potentially stressful work place to block out 74Ⅲ.75 .◆Dividing a day into 76 for chores and errands to be done.as well as arranging time for relaxationIV.Taking breaks.◆Wisely using time to have a drink, watch TV quietly instead of 77 ; just resting your brain2.78 for easily losing focus◆Having too much on minds◆79 all dayConclusion Keeping 80 between extremely relaxed brain and too active brain.Section B (10 marks)Directions Read.the following passage.Answer the questions according to the information given in the passage and the required words limit.Write your answers on your answer sheet.When I was 10 years old, my friend Sydney was diagnosed with a brain tumor.Sydney fought against it, but the tumor did not respond to treatment, and could not be surgically removed.The mass wrapped around her brain stem, the area of the brain that controls the vital functions of life such as breathing and blood pressure.Sydney died at the age of 11.After her death, I felt immense sadness and frustration about pediatric cancer.I decided to turn these negative emotions into positive actions.When I was 11 years old.I founded the Pink Polka Dots Guild(PPD)with two friends.The guild is named after Sydney s favorite color and pattern, which represents both the memory of my friend and the guild's positive approach.My goal has been to raise enough money to find a cure for brain cancer, which is the second most common cancer in children.Over the years, PPD has held fundraisers from lemonade stands to art expositions to golf tournaments.I have played a leading role in planning and organizing each PPD event.The very first Pink Polka Dots event, a garage sale.raised $ 9.000, and our most recent fundraiser, the fifth annual golf tournament, brought in over $ 73.000.The guild progressed faster than I ever anticipated.In five years, we have become 40 members strong, and raised almost half of a million dollars.I've been shocked by the public recognition that the guild has earned.PPD received an award from a U.S.Senator, spoke at a TED Conference, was featured in Teen Vogue, and appeared on The Note Berkus Show.Each of these honors has raised awareness and money for our cause.The initiative that I have taken has truly impacted the world of cancer research.PPD has provided start-up funding for scientific discoveries, such as "Tumor Paint", which illuminates cancerous cells so that surgeons can remove them with unprecedented accuracy.The discovery appeared in Time Magazine., and will be reviewed by the Food & Drug Administration starting in early 2012.1 am extremely proud to have helped fund the research of this life-saving technology.Pink Polka Dots has inspired me to be an activist.My experience has taught me that with passion and dedication, it is possible to make a difference to the world.The determination that Pink Polka Dots sparked in me has carried over to all aspects of my life, making me a driven academic, a competitive debater and a dedicated volunteer.81.Why did the author feel sad and frustrated? (No more than 8 words)82.What was the author s purpose of founding PPD? (No more than 15 words)83.What achievement has PPD made in helping cancer research? (No more than 13 words)84.What did the author learn trom his own experience of founding PPD? (No more than 15 words)Section C (25 marks)Directions Write, an English composition according to the instructions given below.现今,中学生由于学业繁重几乎都没有在家承担任何家务责任。

湖南省长沙市第一中学2022-2023学年高三上学期月考(四)数学试题含答案

湖南省长沙市第一中学2022-2023学年高三上学期月考(四)数学试题含答案

长沙市一中2023届高三月考试卷(四)数学时量:120分钟满分:150分一、单项选择题:本题共8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.集合{}38A x x =∈<<N ,{}6,7,8B =,全集U A B =⋃,则()U A B ⋂ð的所有子集个数()A .2B .4C .8D .162.已知复数z 满足i 3i 4z =+,其中i 为虚数单位,则z 在复平面内对应点在()A .第一象限B .第二象限C .第三象限D .第四象限3.在ABC △中,点N 满足2AN NC = ,记BN a = ,NC b = ,那么BA = ()A .2a b- B .2a b + C .a b - D .a b +4.已知1lg 2a =,0.12b =,sin 3c =,则()A .a b c>>B .b c a >>C .b a c >>D .c b a >>5.2022年9月16日,接迎第九批在韩志愿军烈士遗骸回国的运—20专机在两架歼—20战斗机护航下抵达沈阳国际机场。

歼—20战机是我国自主研发的第五代最先进的战斗机,它具有高隐身性、高态势感知、高机动性能等特点,歼—20机身头部是一个圆锥形,这种圆锥的轴截面是一个边长约为2米的正三角形则机身头部空间大约()立方米A B .33πC D .22π6.已知函数()1cos 32πf x x ω⎛⎫=-- ⎪⎝⎭(0ω>),将()f x 的图象上所有点的横坐标缩短为原来的12,纵坐标不变,得到函数()g x 的图象,已知()g x 在[]0,π上恰有5个零点,则ω的取值范围是()A .82,3⎡⎫⎪⎢⎣⎭B .72,3⎛⎤ ⎥⎝⎦C .82,3⎛⎤ ⎥⎝⎦D .72,3⎡⎫⎪⎢⎣⎭7.用1,2,3,4,5,6组成六位数(没有重复数字),在任意相邻两个数字的奇偶性不同的条件下,1和2相邻的概率是()A .518B .49C .59D .13188.已知三棱柱111ABC A B C -中,12AB AA ==,BC =,当该三棱柱体积最大时,其外接球的体积为()A .2821π27B .32π3C .205π3D .287π9二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的选项中,有多项符合题目要求,全部选对的得5分,有选错的得0分,部分选对的得2分.9.如图,点A ,B ,C ,M ,N 是正方体的顶点或所在棱的中点,则满足MN ∥平面ABC 的有()A .B.C.D .10.已知抛物线C :214y x =的焦点为F ,P 为C 上一点,下列说法正确的是()A .C 的准线方程为116y =-B .直线1y x =-与C 相切C .若()0,4M ,则PM的最小值为D .若()3,5M ,则PMF △的周长的最小值为1111.已知数列{}n a 中,11a =,若11n n n na a n a --=+(2n ≥,n *∈N ),则下列结论中正确的是()A .3611a =B .11112n n a a +-≤C .ln(1)1n a n ⋅+<D .21112n n a a -≤12.已知偶函数()f x 在R 上可导,()01f =-,()()g x f x '=,若()()112f x f x x +--=,则()A .()00g =B .()20232023g =C .()33f =D .()2221f n n -=-(n ∈N )三、填空题:本题共4小题,每小题5分,共20分.13.已知圆C :()22116x y -+=,若直线l 与圆C 交于A ,B 两点,则ABC △的面积最大值为______.14.若(3nx +的展开式的所有项的系数和与二项式系数和的比值是32,则展开式中3x 项的系数是______.15.已知点1F 是椭圆22221x y a b+=(0a b >>)的左焦点,过原点作直线l 交椭圆于A ,B 两点,M ,N分别是1AF ,1BF 的中点,若存在以MN 为直径的圆过原点,则椭圆的离心率的范围是______.16.设函数()2322f x x ax =-(0a >)的图象与()2ln g x a x b =+的图象有公共点,且在公共点处切线方程相同,则实数b 的最大值为______.四、解答题:本题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.17.(本小题满分10分)已知数列{}n a 的前n 项和n S 满足:()231n n S a =-,*n ∈N .(1)求{}n a 的通项公式;(2)设n n b na =,求数列{}n b 的前n 项和n T .18.(本题满分12分)设ABC △的内角A ,B ,C 的对边分别为a ,b ,c ,面积为S ,已知D 是BC 上的点,AD 平分BAC ∠.(1)若2π3BAC ∠=,4AB =,2AC =,求AD 的值;(2)若ABC △为锐角三角形,请从条件①、条件②、条件③这三个条件中选择一个作为已知,求BDDC的取值范围.条件①:)2224b c a S +-=;条件②:224sin 8sin102BB --=;条件③:222sin cos cos sin B C A A B +-=.注:如果选择多个条件分别解答,按第一个解答计分.19.(本题满分12分)如图,点E 在ABC △内,DE 是三棱锥D ABC -的高,且2DE =.ABC △是边长为6的正三角形,5DB DC ==,F 为BC 的中点.(1)证明:点E 在AF 上;(2)点G 是棱AC 上的一点(不含端点),求平面DEG 与平面BCD 所成夹角余弦值的最大值.20.(本题满分12分)已知双曲线C :22221x y a b-=(0a >,0b >)经过点()2,3-,两条渐近线的夹角为60°,直线l 交双曲线C 于A ,B 两点.(1)求双曲线C 的方程;(2)若动直线l 经过双曲线的右焦点2F ,是否存在x 轴上的定点(),0M m ,使得以线段AB 为直径的圆恒过M 点?若存在,求实数m 的值;若不存在,请说明理由.21.(本小题满分12分)某中学2022年10月举行了2022“翱翔杯”秋季运动会,其中有“夹球跑”和“定点投篮”两个项目,某班代表队共派出1男(甲同学)2女(乙同学和丙同学)三人参加这两个项目,其中男生单独完成“夹球跑”的概率为0.6,女生单独完成“夹球跑”的概率为a (00.4a <<).假设每个同学能否完成“夹球跑”互不影响,记这三名同学能完成“夹球跑”的人数为ξ.(1)证明:在的概率分布中,()1P ξ=最大.(2)对于“定点投篮”项目,比赛规则如下:该代表队先指派一人上场投篮,如果投中,则比赛终止,如果没有投中,则重新指派下一名同学继续投篮,如果三名同学均未投中,比赛也终止.该班代表队的领队了解后发现,甲、乙、丙三名同学投篮命中的概率依次为()i t P i ξ==(1i =,2,3),每位同学能否命中相互独立.请帮领队分析如何安排三名同学的出场顺序,才能使得该代表队出场投篮人数的均值最小?并给出证明.22.(本小题满分12分)已知函数()sin ln f x x x m x =-+,0m ≠.(1)若函数()f x 在()0,+∞上是减函数,求m 的取值范围;(2)设3ππ,2α⎛⎫∈ ⎪⎝⎭,且满足cos 1sin ααα=+,证明:当20sin m a α<<-时,函数()f x 在()0,2π上恰有两个极值点.长沙市一中2023届高三月考试卷(四)数学参考答案一、单项选择题:本题共8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.题号12345678答案CAABBDCC1.C【解析】依题意,{}4,5,6,7A =,而{}6,7,8B =,则{}4,5,6,7,8U =,{}6,7A B ⋂=,因此(){}4,5,8U A B ⋂=ð,所以()U A B ⋂ð的所有子集个数是328=.故选:C .2.A 【解析】由题得3i 434i iz +==-,所以34i z =+.所以z 在复平面内对应点在第一象限.故选:A .3.A 【解析】22BA BN NA BN NC a b =+=-=-.故选:A .4.B 【解析】1lg lg102a =<=,0.10221b =>=,0sin31<<,∴b c a >>.故选:B .5.B 【解析】根据圆锥的轴截面是一个边长约为2米的正三角形可知,圆锥底面半径为1米,米,根据圆雉体积公式得213π1π33V =⨯=.故选:B .6.D【解析】()π1cos 232g x x ω⎛⎫=-- ⎪⎝⎭,令π23t x ω=-,由题意()g x 在[]0,π上恰有5个零点,即1cos 2t =在ππ,2π33t ω⎡⎤∈--⎢⎥⎣⎦上恰有5个不相等的实根,由cos y t =的性质可得11ππ13π2π333ω≤-<,解得723ω≤<.故选:D .7.C【解析】将3个偶数排成一排有33A 种,再将3个奇数分两种情况揷空有332A 种,所以任意相邻两个数字的奇偶性不同的6位数有33332A A 72=种,任意相邻两个数字的奇偶性不同且1和2相邻,分两种情况讨论:当个位是偶数:2在个位,则1在十位,此时有2222A A 4=种;2不在个位:将4或6放在个位,百位或万位上放2,在2的两侧选一个位置放1,最后剩余的2个位置放其它两个奇数,此时有11122222C C C A 16=种;所以个位是偶数共有20种;同理,个位是奇数也有20种,则任意相邻两个数字的奇偶性不同且1和2相邻的数有40种,所以任意相邻两个数字的奇偶性不同的条件下,1和2相邻的概率是405729=.故选:C .8.C 【解析】解法一:因为三棱柱111ABC A B C -为直三棱柱,所以1AA ⊥平面ABC ,所以要使三棱柱的体积最大,则ABC △面积最大,因为1sin 2ABC S BC AC ACB =⋅⋅∠△,令AC x =,因为BC =,所以23sin 2ABC S x ACB =⋅∠△,在ABC △中,2222cos 2AC BC AB ACB AC BC +-∠==⋅,所以()224224416143216sin 11212x x x ACB x x--+-∠=-=,所以()()22422424123384sin 34434ABC x x x S x ACB ∠--+-+-=⋅=⋅=△,所以当24x =,即2AC =时,()2ABC S △取得最大值3,所以当2AC =时,ABC S △,此时ABC △为等腰三角形,2AB AC ==,BC =,所以22244121cos 22222AB AC BC BAC AB AC +-+-∠===-⋅⨯⨯,()0,πBAC ∠∈,所以2π3BAC ∠=,由正弦定理得ABC △外接圆的半径r 满足23422πsin3r ==,即2r =,所以直三棱柱111ABC A B C -外接球的半径222152AA R r ⎛⎫=+= ⎪⎝⎭,即R =所以直三棱柱111ABC A B C -外接球的体积为34π205π33R =.故选:C .解法二:在平面ABC 中,由2AB =,BC =知,平面ABC 中C 点的轨迹是阿氏圆,建立坐标系.要使三棱柱的体积最大,则ABC △面积最大,此时可计算出外接圆半径为2.所以直三棱柱111ABC A B C -外接球的半径2221252AA R ⎛⎫=+= ⎪⎝⎭,即R =所以直三棱柱111ABC A B C -外接球的体积为34π33R π=.二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的选项中,有多项符合题目要求,全部选对的得5分,有选错的得0分,部分选对的得2分.题号9101112答案ADBCABCABD9.AD【解析】对于A 选项,由图1可知MN DE AC ∥∥,MN ⊄平面ABC ,AC ⊂平面ABC ,所以MN ∥平面ABC ,A 正确;对于B 选项,设H 是EG 的中点,由图2,结合正方体的性质可知,AB NH ∥,MN AH BC ∥∥,AM CH ∥,所以A ,B ,C ,H ,N ,M 六点共面,B 错误;对于C 选项,如图3所示,根据正方体的性质可知MN AD ∥,由于AD 与平面ABC 相交,所以MN 与平面ABC 相交.所以C 错误;对于D 选项,如图4,设AC NE D ⋂=,由于四边形AECN 是矩形,所以D 是NE 中点,由于B 是ME 中点,,所以MN BD ∥,由于MN ⊄平面ABC ,BD ⊂平面ABC ,所以MN ∥平面ABC ,D正确.故选:AD .10.BCD 【解析】拋物线C :214y x =,即24x y =,所以焦点坐标为()0,1F ,准线方程为1y =-,故A 错误;由21,41,y x y x ⎧=⎪⎨⎪=-⎩即2440x x -+=,解得()24440∆=--⨯=,所以直线1y x =-与C 相切,故B 正确;点(),P x y ,所以()()22222441621212PM x y y y y =+-=-+=-+≥,所以minPM=,故C 正确;如图过点P 作PN ⊥准线,交于点N ,NP PF =,5MF ==,所以周长5611PFM C MF MP PF MF MP PN MF MN =++=++≥+=+=△,当且仅当M 、P 、N 三点共线时取等号,故D 正确;故选:BCD .11.ABC【解析】因为11n n n na a n a --=+,故可得1111n n a a n --=,11221111111111111112n n n n n a a a a a a a a n n ---⎛⎫⎛⎫⎛⎫=-+-+⋅⋅⋅+-+=++⋅⋅⋅++ ⎪ ⎪ ⎪-⎝⎭⎝⎭⎝⎭,对A :当3n =时,3111111236a =++=,故可得3611a =,故A 正确;对B :因为1111n n a a n --=,则11111n n a a n +-=+对1n =也成立,又当1n ≥,*n ∈N 时,1112n ≤+,则11112n n a a +-≤,故B 正确;对C :令()()ln 1f x x x =+-(0x >),则()01xf x x -=<+',故()f x 在()0,+∞上单调递减,则()()00f x f <=,则当0x >时,()ln 1x x +<,11ln 1x x⎛⎫+< ⎪⎝⎭;则当1n ≥,*n ∈N 时,11ln 1n n⎛⎫+<⎪⎝⎭,即()1ln 1ln n n n +-<;则()()()()11ln 1ln 1ln ln ln 1ln2ln111n n n n n n n +=+-+--+⋅⋅⋅+-<++⋅⋅⋅+⎡⎤⎡⎤⎣⎦⎣⎦-,即()1ln 1nn a +<,又0n a >,()ln 11n a n ⋅+<,故C 正确;对D :2111111112222n n n a a n n n n -=++⋅⋅⋅+≥⨯=++,故D 错误.故选:ABC .12.ABD 【解析】因为函数()f x 为偶函数,所以()f x 的图象在0x =处的斜率为0,即()()000g f ='=,故A 正确;函数()f x 为偶函数,所以()g x 为奇函数,()()112f x f x x +--=,所以()()112g x g x ++-=,令0x =,得()11g =,又()g x 为奇函数,所以()()112g x g x +--=,()()()()()()()()202320232021202120193112101112023g g g g g g g g =-+-+⋅⋅⋅+-+=⨯+=,故B 正确;假设()2112f x x =-,满足()f x 为偶函数,()01f =-,()()()()22111111222f x f x x x x +--=+--=,符合题目的要求,此时,()732f =,故C 错;()f x 为偶函数,所以()()112f x f x x +--=,即()()112f x f x x --+=-,()()()()()()()()22222224200f n f n f n f n f n f f f -=---++-+--++⋅⋅⋅+--+()()()()221222122322111212n n n n n --+⎡⎤⎣⎦=-----⋅⋅⋅-⋅--=-=-(n ∈N ),故D 正确.故选:ABD .三、填空题:本题共4小题,每小题5分,共20分.13.8【解析】圆C :()22116x y -+=的圆心为()1,0,半径为4,设线段AB 的中点为M ,由垂径定理得:2216AM MC +=,由基本不等式可得:22162AM MC AM MC +=≥⋅,所以8AM MC ⋅≤,当且仅当AM MC =时,等号成立,则182ABC S AB CM AM CM =⋅=⋅≤△,故答案为:8.14.15【解析】令1x =,得所有项的系数和为4n,二项式系数和为2n,所以42322n nn ==,即5n =,(53x +的第1r +项为()15552255C 3C 3rrr r r r x x x ---⎛⎫⋅⋅=⋅⋅ ⎪⎝⎭,令532r -=,得4r =,所以3x 项的系数是45C 315⨯=,故答案为:15.15.22⎫⎪⎪⎣⎭【解析】如图所示,当点M ,N 分别是1AF ,1BF 的中点时,OM ,ON 是1ABF △的两条中位线,若以MN 为直径的圆过原点,则有OM ON ⊥,11AF BF ⊥,解法一:所以在直角1ABF △中,122AB OF c ==,即A 、B 为以原点为圆心,c 为半径的圆与椭圆的交点,所以b c ≤,即22b c ≤,所以222a c ≤,故22e ≤,又1e <,所以212e ≤<.解法二:由上可知,11AF BF ⊥,设点()00,A x y ,则点()00,B x y --,又点()1,0F c -,所以()100,AF c x y =--- ,()100,BF c x y =-+,则22211000AF BF c x y ⋅=--= ,又2200221x y a b +=,所以2222020c x b c a +-=,得()222202a cb xc -=,即只需()222220a c b a c -≤<,整理得:222c a ≥,解得22e ≤,又1e <,所以212e ≤<.故答案为:2,12⎫⎪⎪⎣⎭.16.212e【解析】设公共点坐标为()00,x y ,则()32f x x a =-',()2a g x x'=(0x >),所以有()()00f x g x ='',即20032a x a x -=,解得0x a =(03ax =-舍去),又()()000y f x g x ==,所以有2200032ln 2x ax a x b -=+,故2200032ln 2b x ax a x =--,所以有221ln 2b a a a =--,对b 求导有()21ln b a a =-+',故b 关于a 的函数在10,e ⎛⎫ ⎪⎝⎭为增函数,在1,e ⎛⎫+∞ ⎪⎝⎭为减函数,所以当1ea =时b 有最大值212e .故答案为:212e .四、解答题:本题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.17.【解析】(1)由已知()231n n S a =-,*n ∈N ,当1n =时,()11231S a =-,解得113a S ==,当2n ≥时,()11231n n S a --=-,则()()123131n n n a a a -=---,即13n n a a -=,所以数列{}n a 是以3为首项,3为公比的等比数列,所以1333n n n a -=⨯=;(2)由(1)得3n n a =,则3nn n b na n ==⋅,所以()231132333133n n n T n n -=⨯+⨯+⨯+⋅⋅⋅+-⨯+⨯①,()23413132333133n n n T n n +=⨯+⨯+⨯+⋅⋅⋅+-⨯+⨯②,①-②得()()1231131332132333333132n n nn n n n T n n +++-----=+++⋅⋅⋅+-⨯=⨯=-,所以()132134n n n T ++-=.18.【解析】(1)依题意可得ABD ACD S S S =+△△,可得111sin sin sin 222AB AC BAC AB AD BAD AD AC DAC ⋅⋅∠=⋅⋅∠+⋅⋅∠,又因为AD 平分BAC ∠,且2π3BAC ∠=,所以1π3BAD DAC ∠=∠=,则1114242222222AD AD ⨯⨯⨯=⨯⨯⨯+⨯⨯⨯,整理可得43AD =.(2)选条件①:)22214sin 2b c abc A +-=⨯,222sin 2b c a A bc+-=sin A A =,即tan A =∵π0,2A ⎛⎫∈ ⎪⎝⎭,∴π3A =,在ABD △中,由正弦定理得sin sin BD ABBAD ADB=∠∠,∴sin sin AB BAD BD ADB ⋅∠=∠,在ADC △中,由正弦定理得sin sin CD ACCAD ADC=∠∠,∴sin sin AC CAD CD ADC ⋅∠=∠,∵AD 平分BAC ∠,ADB ∠与ADC ∠互补,∴2πsin 31sin cos sin sin 313sin 22sin sin sin sin 2tan 2sin AB BAD B B BBD AB c C ADB AC CAD DC AC b BB B B ADC⎛⎫⋅∠-+ ⎪⎝⎭∠=======+⋅∠∠.∵ABC △是锐角三角形,∴ππ62B <<,∴tan 3B >,∴131222tan 2B <+<,即BD DC 的取值范围为1,22⎛⎫⎪⎝⎭.选条件②:∵21cos 4sin 8102BB --⨯-=,∴24sin 4cos 50B B +-=,∴()241cos 4cos 50B B -+-=,∴()22cos 10B -=,∴1cos 2B =,∵π0,2B ⎛⎫∈ ⎪⎝⎭,∴π3B =,在ABD △中,由正弦定理得sin sin BD ABBAD ADB=∠∠,∴sin sin AB BAD BD ADB ⋅∠=∠,在ADC △中,由正弦定理得sin sin CD ACCAD ADC=∠∠,∴sin sin AC CAD CD ADC ⋅∠=∠,∵AD 平分BAC ∠,ADB ∠与ADC ∠互补,∴sin sin sin 23sin sin sin πsin 3sin sin 3AB BAD BD AB c C C ADB C AC CAD DC AC b B ADC ⋅∠∠======⋅∠∠.∵ABC △是锐角三角形,∴ππ62C <<,∴1sin 12C <<,∴32323sin 333C <<,∴BDDC 的取值范围为323,33⎛⎫ ⎪ ⎪⎝⎭.选条件③:∵()()222sin 1sin 1sin sin B C A A B +---=,∴222sin sin sin sin B A C A B +-=,由正弦定理得222a b c +-=,∴根据余弦定理得22233cos 222a b c C ab ab +-===,∵π0,2C ⎛⎫∈ ⎪⎝⎭,∴π6C =,在ABD △中,由正弦定理得sin sin BD AB BAD ADB =∠∠,∴sin sin AB BADBD ADB⋅∠=∠,在ADC △中,由正弦定理得sin sin CD ACCAD ADC=∠∠,∴sin sin AC CAD CD ADC ⋅∠=∠,∵AD 平分BAC ∠,ADB ∠与ADC ∠互补,∴sin 1sin 1sin 2sin sin sin 2sin sin AB BAD BD AB c CADB AC CAD DC AC b B B BADC∠∠∠∠⋅======⋅.∵ABC △是锐角三角形,∴ππ32B <<,∴sin 12B <<,∴11sin B <<,∴1122sin 3B <<,∴BDDC 的取值范围为13,23⎛⎫ ⎪ ⎪⎝⎭.19.【解析】(1)证明:连接EF ,DF .因为DE 是三棱锥D ABC -的高,即DE ⊥平面ABC ,因为BC ⊂平面ABC ,所以DE BC ⊥.因为5DB DC ==,BC 的中点为F ,所以DF BC ⊥,因为DE DFD ⋂=,DE ,DF ⊂平面DEF ,所以BC ⊥平面DEF ,因为EF⊂平面DEF,所以BC EF⊥.又因为ABC△是边长为6的正三角形,BC的中点为F,所以BC AF⊥,即点E在AF上.(2)结合(1)得,AF=4DF==,EF==,AE AF EF=-=.过点E作EH BC∥,交AC于H,结合(1)可知EF,EH,ED两两垂直,所以以E为坐标原点,EF,EH,ED的方向分别为x,y,z轴,建立如图所示的空间直角坐标系,()A,()3,0B-,()C,()0,0,2D所以()2BD=-,()0,6,0BC=.设平面BCD的法向量为()111,,m x y z=,则0,0,BD mBC m⎧⋅=⎪⎨⋅=⎪⎩即1111320,60,y zy⎧-++=⎪⎨=⎪⎩取11x=,则(m=.又()AC=,设AG ACλ=,()0,1λ∈.所以()()(),0EG EA ACλλλ=+=+=-.设平面DEG的法向量为()222,,u x y z=,则0,0,ED uEG u⎧⋅=⎪⎨⋅=⎪⎩即(22220,30,zx yλ=⎧⎪⎨+=⎪⎩取2x=,则13,0uλ⎫=-⎪⎭.所以1cos,2u mu mu m⋅==≤,当且仅当13λ=时,等号成立.所以平面DEG与平面BCD所成夹角余弦值的最大值为12.20.【解析】(1)∵两条渐近线的夹角为60°,∴渐近线的斜率ba±=或33±,即b=或33b a=;当b =时,由22491a b-=得:21a =,23b =,∴双曲线C 的方程为:2213y x -=;当33b a =时,方程22491a b-=无解;综上所述,双曲线C 的方程为:2213y x -=.(2)由题意得:()22,0F ,假设存在定点(),0M m 满足题意,则0MA MB ⋅=恒成立;方法一:①当直线l 斜率存在时,设l :()2y k x =-,()11,A x y ,()22,B x y ∴212243k x x k +=-,2122433k x x k +=-,∴()()()()2212121212121224MA MB x m x m y y x x m x x m k x x x x ⋅=--+=-+++-++⎡⎤⎣⎦()()()()()()2222222222121222431421244033k k k k m k x x k m x x m k m k k k +++=+-++++=-++=--,∴()()()()()222222243142430k k k k m m k k++-+++-=,整理可得:()()22245330k m m m --+-=,由22450,330m m m ⎧--=⎨-=⎩得:1m =-;∴当1m =-时,0MA MB ⋅=恒成立;②当直线l 斜率不存在时,l :2x =,则()2,3A ,()2,3B -,当()1,0M -时,()3,3MA = ,()3,3MB =-,∴0MA MB ⋅= 成立;综上所述,存在()1,0M -,使得以线段AB 为直径的圆恒过M 点.方法二:①当直线l 斜率为0时,l :0y =,则()1,0A -,()1,0B ,∵(),0M m ,∴()1,0MA m =-- ,()1,0MB m =-,∴210MA MB m ⋅=-= ,解得1m =±;②当直线l 斜率不为0时,设l :2x ty =+,()11,A x y ,()22,B x y 由222,13x ty y x =+⎧⎪⎨-=⎪⎩得,()22311290t y ty -++=,∴()22310,12330,t t ⎧-≠⎪⎨∆=+>⎪⎩∴1221231t y y t +=--,122931y y t =-,∴()()()21212121212MA MB x m x m y y x x m x x m y y ⋅=--+=-+++ ()()()()()()222121212121222221244ty ty m ty ty m y y t y y t mt y y m m =++-+++++=++-++-+()()()()222222291122121594420313131t t t mt m t m m m t t t +--+=-+-+=+-=---;当1215931m -=-,即1m =-时,0MA MB ⋅= 成立;综上所述,存在()1,0M -,使得以线段AB 为直径的圆恒过M 点.21.【解析】(1)由已知,ξ的所有可能取值为0,1,2,3,()()()()22010.610.41P a a ξ==-⋅-=-,()()()()()()21210.6110.6C 10.213P a a a a a ξ==-+-⋅-=-+,()()()()12220.6110.60.432P C a a a a a ξ==⋅-+-=-()230.6P a ξ==∵00.4a <<,∴()()()()100.21130P P a a ξξ=-==-+>,()()()2120.23830P P a a ξξ=-==-+>()()()2130.24230P P a a ξξ=-==-+->所以概率()1P ξ=最大.(2)由(1)知,当00.4a <<时,有()11t P ξ==的值最大,且()()()23230.2670t t P P a a ξξ-==-==->,123t t t >>,所以应当以甲、乙、丙的顺序安排出场顺序,才能使得该代表队出场投篮人数的均值最小.证明如下:假设1p ,2p ,3p 为1t ,2t ,3t 的任意一个排列,即若甲、乙、丙按照某顺序派出,该顺序下三个小组能完成项目的概率为1p ,2p ,3p ,记在比赛时所需派出的小组个数为η,则1η=,2,3,且η的分布列为:η123P1p ()121p p -()()1211p p --数学期望()()()()1121212122131132E p p p p p p p p p η=+-+--=--+,∵123t t t >>,∴11p t ≤,()()()()12121111p p t t --≥--,∴()()()()121212112112123221121132p p p p p p p t t t t t t t --+=+---≥+---=--+,所以应当以甲、乙、丙的顺序安排出场顺序,才能使得该代表队出场投篮人数的均值最小.22.【解析】(1)()cos 1mf x x x=-+',因为函数()f x 在()0,+∞上是减函数,所以()cos 10mf x x x=-+≤'在()0,+∞上恒成立,当0m <时,()cos 10mf x x x=-+≤'在()0,+∞上恒成立,满足题意;当0m >时,当0,2m x ⎛⎫∈ ⎪⎝⎭时,由2m x >,故()cos 1cos 12cos 10m f x x x x x =-+>'-+=+≥,与()0f x '≤在()0,+∞上恒成立矛盾,所以m 的取值范围为(),0-∞.(2)令()cos 10mf x x x=-+='得cos m x x x =-,令()cos g x x x x =-,()0,2πx ∈,则()1cos sin g x x x x =-+',所以当(]0,πx ∈时,()0g x '>,函数()g x 在(]0,π上单调递增,当3ππ,2x ⎛⎤∈ ⎥⎝⎦时,()2sin cos 0g x x x x =+'<',故函数()g x '在3ππ,2⎛⎤ ⎥⎝⎦上单调递减,因为()π20g '=>,3π3π1022g ⎛⎫=-<⎪⎝⎭',所以存在13ππ,2x ⎛⎫∈ ⎪⎝⎭,使得()10g x '=,即1111cos sin 0x x x -+=,所以当()1π,x x ∈时,()0g x '>,()g x 在()1π,x 上单调递增;当13π,2x x ⎛⎫∈ ⎪⎝⎭时,()()0,g x g x '<在13π,2x ⎛⎫ ⎪⎝⎭上单调递减;当3π,2π2x ⎛⎫∈⎪⎝⎭时,()3cos sin 0g x x x x '''=->恒成立,所以()g x ''在3π,2π2⎛⎫⎪⎝⎭上单调递增,因为3π202g ⎛⎫=-<⎪⎝⎭'',()2π2π0g ='>',所以存在23π,2π2x ⎛⎫∈ ⎪⎝⎭,使得()0g x ''=,即2222sin cos 0x x x +=,所以当23π,2x x ⎛⎫∈⎪⎝⎭时,()0g x ''<,()g x '单调递减,当()2,2πx x ∈时,()0g x ''>,()g x '单调递增,因为3π3π1022g ⎛⎫=-<⎪⎝⎭',()2π0g '=,所以()g x 在3π,2π2⎛⎫ ⎪⎝⎭上单调递减,综上,函数()g x 在()10,x 上单调递增,在()1,2πx 上单调递减,且()()02π0g g ==,()()1111cos g x x x =-,因为()11111cos sin 0g x x x x '=-+=,即1111sin cos x x x +=,所以()()2111111cos sin g x x x x x =-=-,所以()()21110sin g x g x x x <≤=-,其中13ππ,2x ⎛⎫∈ ⎪⎝⎭,所以当2110sin m x x <<-时,直线y m =与()y g x =的图象在()0,2π上有两个交点,所以()f x '在()0,2π上有两个变号零点,即()f x 在()0,2π上有两个极值点.所以取1x α=,则cos 1sin ααα=+,当20sin m αα<<-时,()f x 在()0,2π上有两个极值点.。

湖南省长沙市长郡中学2024届高三上学期开学考试(暑假作业检测)数学试题(含解析)

湖南省长沙市长郡中学2024届高三上学期开学考试(暑假作业检测)数学试题(含解析)

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湖南省长沙市长郡中学2015届高三上学期第二次月考数学(理)试题 Word版含解析

湖南省长沙市长郡中学2015届高三上学期第二次月考数学(理)试题 Word版含解析

湖南省长沙市长郡中学2015届高三上学期第二次月考数学(理)试题(解析版)得分:____________ 【试卷综析】本试卷是高三月考理科试卷,是一次摸底考试,也是一次模拟考试,命题模式与高考一致,考查了高考考纲上的诸多热点问题,突出考查考纲要求的基本能力,重视学生基本数学素养的考查。

知识考查注重基础、注重常规,也有综合性较强的问题,试题必做部分重点考查:函数、三角函数、数列、立体几何、概率、解析几何等,涉及到的基本数学思想有数形结合、函数与方程、转化与化归、分类讨论等,试题难度适中,兼达到高考关于区分度的要求,适合高三学生模拟考试使用。

本试题卷包括选择题、填空题和解答题三部分,共8页。

时量120分钟。

满分150分。

一、选择题:本大题共10小题,没小题5分,共50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.“0x <”是“()ln 10x +<”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 【知识点】充分、必要条件的判断 A2【答案解析】B 解析:0x <时,11x +<,则()()ln 1010x x +<-<<时或()ln 1x +不存在()1x ≤-时,所以“0x <”是“()ln 10x +<”的不充分条件;()ln 10x +<时,011x <+<,即10x -<<,则0x <成立,所以“0x <”是“()ln 10x +<”的必要条件。

【思路点拨】根据不等式的性质,利用充分条件和必要条件的定义进行判断即可得到结论。

2.已知函数33y x x c =-+的图像与x 轴恰有两个公共点,则c = A.-2或2 B.-9或3 C.-1或1 D.-3或1 【知识点】导数与极值 B12【答案解析】A 解析:求导函数可得()()2'33311y x x x =-=+-令'0y >,可得11x x <->或;令'0y <,可得11x -<<; ∴函数在()(),1,1,-∞-+∞上单调增,在()1,1-上单调递减 ∴函数在1x =-处取得极大值,在1x =处取得极小值 ∵函数33y x x c =-+的图像与x 轴恰有两个公共点 ∴极大值等于0或极小值等于0∴130130c c -+=-++=或 ∴22c c ==-或 故选A .【思路点拨】求导函数,确定函数的单调性,确定函数的极值点,利用函数33y x x c =-+的图象与x 轴恰有两个公共点,可得极大值等于0或极小值等于0,由此可求c 的值3.已知函数()sin f x x ω=在,则实数ω的一个值可以是【知识点】函数()()sin f x A x ωϕ=+的性质 C4【答案解析】C 解析:函数()sin f x x ω=在故选:C,从而可求ω的一个值。

2024届湖南长沙市长郡中学高三摸底(4月)调研测试英语试题含解析

2024届湖南长沙市长郡中学高三摸底(4月)调研测试英语试题含解析

2024届湖南长沙市长郡中学高三摸底(4月)调研测试英语试题注意事项:1.答卷前,考生务必将自己的姓名、准考证号填写在答题卡上。

2.回答选择题时,选出每小题答案后,用铅笔把答题卡上对应题目的答案标号涂黑,如需改动,用橡皮擦干净后,再选涂其它答案标号。

回答非选择题时,将答案写在答题卡上,写在本试卷上无效。

3.考试结束后,将本试卷和答题卡一并交回。

第一部分(共20小题,每小题1.5分,满分30分)1.________ the opportunity to speak at the graduation ceremony made me overjoyed.A.Offering B.OfferedC.To offer D.Being offered2.Another study of 302 volunteers at hospitals in Chicago focused on individual differences in the degree ______ people view “volunteer” as an important social role.A.by which B.to which C.in which D.from which3.— I am worn out. —Me too, all work and no play. So it’s time to ________.A.burn the midnight oil B.push the limitsC.go with the flow D.call it a day4.﹣Mom,I'll stay in to accompany my grandpa this evening.﹣________!A.With pleasure B.Never mindC.Suit yourself D.It depends5._______, the dancers practise hard to make their dreams come true.A.Instead of being disabled B.Being disabledC.Disabled as they are D.In case of being disabled6.Maybe some of you are curious about what my life was like on the streets because I’ve never really talked about it______.A.in place B.in turn C.in force D.in depth7.Her doctor indicated that even adding a(n) _____ amount of daily exercise would dramatically improve her health. A.modest B.equalC.exact D.considerable8.Thinking that her daughter was doing her homework ,the mother left the room, _________.A.quickly and gentle B.quick and gentleC.quickly and gently D.quick and gently9.As you go through this book, you ________ that each of the millions of people who lived through World War II had a different experience.A.will find B.foundC.had found D.have found10.I’m _______Chinese and I do feel ______Chinese language is ____most beautiful language .A./, the, a B.a, /, the C.a, the, / D.a, /, a11.I hope when you come tomorrow, you _____ the reading and have something to share.A.did B.are doingC.will be doing D.will have done12.Whether something is alive or dead is a crucial ______ and it is one that children have no difficulty understanding by the age of five.A.declaration B.distinction C.division D.distribution13.I have often thought it would be a blessing if each human being _______ blind and deaf for a few days at some time in his life.A.has been stricken B.were strickenC.had been D.would be14.I still find it hard to imagine that such a clever child __________ make such a foolish mistake.A.shall B.mustC.can D.should15.—How did it come that you damaged your car so badly?—I ____into a tree on the roadside the other day.A.ran B.had run C.was running D.run16.Peter survived in the accident when he fell overboard yesterday. He _______ escaped drowning.A.nearly B.slightly C.narrowly D.hardly17.Andrew lives alone and enjoys the c ompany of a pet cat _______ he’s grown so fond.A.which B.in whichC.of which D.when18.Although everything seems to have been taken into consideration, ________ accident can happen when the astronauts walk in ________ space.A./; the B.an; the C.the; the D.an; /19.It was ______ we were returning home ______ I realized what a good feeling it was to have helped someone in trouble.A.when; before B.when; thatC.before; where D.how; that20.The doctor’s treatment has worked marvels: the patient has completely.A.repeated B.returned C.recovered D.reminded第二部分阅读理解(满分40分)阅读下列短文,从每题所给的A、B、C、D四个选项中,选出最佳选项。

湖南省长郡中学2018届高三月考(二)英语试题Word版含答案

湖南省长郡中学2018届高三月考(二)英语试题Word版含答案

第二部分阅读理解(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C和D四个选项中,选出最佳选项。

AAn Oceans VacuumThere’s a collection of plastic trash in the middle of the Pacific Ocean. It’s bigger than Texas-and growing. The way to clean it up now is to catch it with nets. That is both costly and slow. Instead, the Ocean Cleanup Project proposes 62-mile-long floating barriers that would use natural currents to trap trash. If next year’s trials succeed, a full cleanup operation would aim to start in 2020. It could reduce the trash by 42% over 10 years.Easy-On ShoesIn 2012, Mathew Walzer, a high school student with a disability, sent a note to Nike. “My dream is o go to college,” he wrote, “without having to worry about someone coming to tie my shoes every day.”Nike assigned a design team to the challenge. This year, they came out with their solution: the FlyEase. The basketball shoe can be fastened with one hand. A pair of Nike FlyEase shoes sells for $130.An Airport for Drones(无人机)As Amazon, Google, and others get ready for drone delivery service, there is one big question: what kinds of home bases will their drones have? Rwanda, in Africa, may have the answer. There, workers will soon start work on three “drone ports”. The goal is to make it easier to transport food, medical supplies, electronics, and other goods through the hilly countryside. Construction is set to be completed in 2020.21.What’s the advantage of the Oceans Vacuum?A. It can be a money-saverB. It can grow year by yearC. It can tear plastic into piecesD. It can be put into wide use soon22.What do we know about Nike?A. It offers free shoes to the disabledB. It is designing new shoes frequentlyC. It provides customer-friendly servicesD. It responded to Matthew’s request passively23.Why is Rwanda setting up “drone ports”?A. Because road travel there is roughB. Because there are too many dronesC. Because they’re easier to construct than roadsD. Because they are receptive to new technologyBI grew up in a troubled home in the 1970s, on the outskirts of downtown Orlando, Florida. Not far away, a three-story house attracted my eyes.It was nothing like the one I lived in with my mother, a small dark place with rules about befriending others. “Don’t. Never, ever talk to anyone,” my mother said.One day, in sixth grade, a black-haired woman was introduced to our class: Mrs. Reese. Reese explained that she was starting Spanish Club. She invited anyone interested in learning Spanish language and culture to stay after school.I could not take my eyes off her bracelets(手镯) and shining rings. The bell rang, and to my shock, no one went up to Mrs. Reese. I was under strict orders to go straight home. But that day, I stayed. I asked Mrs. Reese when the club started.“We could begin right now if you like,”she said with a smile. I felt beautiful. That day I learned that the house of my dreams was her house. I learned how to answer questions about my age and my favorite food in Spanish. And I learned, Do you want to come over tomorrow for cooking lessons?I wanted to say “Yes”, but Mom’s words held me back.I begged my mother all summer and into fall, well after Spanish Club had dissolved. I wept at night sometimes, so worried that Mrs. Reese and her family would move away.At some point, I managed to wear my mother down and one Saturday afternoon. I rode out to Mrs. Reese’s house.The details of that afternoon are marked in my mind: We had tea. She painted my toenails red. We made a garlicky picadillo. We spoke in Spanish. In Spanish, my voice was loud and romantic. This is the real me! I remember thinking.My mother never permitted me another visit to Mrs. Reese’s house. But four decades later, I still remember that day and the life she showed me, proof of a possible future.24.What kind of family was the author from?A. Hard-upB. Two-parentC. Stress-freeD. Disease-ridden25.Why did the author choose to join the club?A. She wanted to stay longer at schoolB. She intended to comfort Mrs. ReeseC. She was deeply attracted by Mrs. ReeseD. She hoped to befriend the owner of her dreamt house26.The author went to Mrs. Reese’s house .A. with the help of her tearsB. while no one was noticingC. with her mother’s permissionD. just before the lady moved away27.What did the author gain from Mrs. Reese?A. The beauty of SpanishB. The wonder of a new worldC. The power of self-confidenceD. The importance of independenceCEnglish is full of colorful phrases to describe shyness. Someone shy might be called shrinking violet or a wallflower, while for especially nervous types we have the curious expression: they wouldn’t say boo to a goose.None of these are traditionally seen as positive descriptions, even if you like geese. In a culture of go-getting, high achievers, shy people don’t come first.Or that's what the self-help industry would have you believe. Bookshops are filled with vital tomes(巨著) that promise to help beat social fears and find success in life, love and business. That is why one book, Shrinking Violets: A Field Guide to Shyness, bucks the trend. It became a sudden success across English-language media recently for its new take-on shyness.Author Joe Moran says that despite struggling with shyness and longing for loneliness all his life, being shy can also be "a gift". Freed from the constant urge to participate and compete in social situations, people are liberated to look at the world in new ways, and gain fresh insights.Indeed, many of the world's great thinkers and artists are introverts(内向的人). Scientists Charles Darwin and Albert Einstein preferred their own company; actress Keira Knightley often finds herself tongue-tied at parties; and Harry Potter author JK Rowling claims she used to be too nervous to even borrow a pen.Moran told BBC Future: "I think shyness probably does turn you into an amateur anthropologist(人类学家), really-you are more likely to be an observer."So, while extroverts make all the noise, they don't necessarily have the best ideas.If you're shy, you've probably known this for a long time. You just don't shout about it.28.When someone is being called a wallflower, he is being .A. praised for his graceB. admired for his characterC. laughed at for his shynessD. told off for his nervousness29.The underlined phrase “bucks the trend” in Paragraph 2 probably means ””.A. going against the trend and succeedsB. changing the public idea completelyC. becoming unpopular and unacceptedD. becoming the major concern of people30.The author mentioned many famous shy people in order to .A. point out the harm shyness bringsB. disconnect shyness and successC. shows the reasons for shynessD. prove shyness contributes to science31.What is the author’s attitude towards shyness?A. OpposedB. IndifferentC. SupportiveD. CriticalDFrigatebirds seagoing fliers with a 6-foot wingspan, can stay aloft(up in the air) for weeks at a time, a new study has found.Since the frigatebird spends most of its life at sea, its habits outside of when it reproduces on land aren’t well-known-until researchers started tracking them around the Indian Ocean. What the researchers discovered is that the bird’s flying ability is unbelievable.Ornithologist(鸟类学家) Henri Weimerskirch put satellite tage(标签) on a couple of dozen frigatebirds. When the data started to come in, he could hardly believe how high the birds flew."First, we found, 'Whoa, 1,500 meters. Excellent,' " says Weimerskirch, "And after 2,000, after 3,000, after 4,000 meters-OK, at this altitude they are in freezing conditions, especially surprising for a tropical bird.""There is no other bird flying so high relative to the sea surface," he says. "It's the only bird that is known to intentionally enter into a cloud," Weimerskirch says. And not just any cloud-a soft, white cumulus cloud(积云). Over the ocean, these clouds tend to form in places where warm air rises from the sea surface. The birds take a ride on the current of rising air, all the way up to the top of the cloud.Frigatebirds have to find ways to stay aloft because they can't land on the water. Since their feathers aren't waterproof, the birds would drown in short order. They feed by harassing other birds in flight until they bring whatever fish they've swallowed back into their mouth and the frigatebird takes it.So in between meals, frigatebirds fly higher... and higher.In one case, for two months-continuously aloft.One of the tagged birds flew 40 miles without a wing-flap. Several covered more than 300 miles a day on average, and flew continuously for weeks. They are blessed with an unusual body. No bird has a larger wing surface area compared with body weight.32.How did researchers feel when data about frigatebirds reached them?A. CalmB. SurprisedC. HopefulD. Anxious33.According to the text, how can frigatebirds fly so high?A. By flying into a cloudB. With the help of researchersC. Thanks to advanced technologyD. By following other birds into the sky34.What does the underlined word ”they” in the text refer to?A. FrigatebirdsB. Other birdsC. Small fishD. Larger fish35.In what aspect are frigatebirds different from other birds?A. When they give birthB. What they feed onC. Their body weightD. Their wing surface area第二节(共5小题;每小题2分,满分10分)根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。

湖南省长沙市长郡中学2022-2023学年高三上学期月考 数学

湖南省长沙市长郡中学2022-2023学年高三上学期月考 数学

长郡中学2023届高三月考试卷数 学本试卷共8页。

时量120分钟,满分150分。

一、选择题:本题共8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.已知集合||1|1,{} ==--∈A y y x x R ,{}3|log 1,=≥B x x ,则A∩=RBA .{|1}≥-x xB .{}|3<x xC .}{|13-≤≤x xD .{}|13-≤<x x2.若复数z 满足||2,3-=⋅=z z z z ,则2z 的实部为A -2B .-1C .1D . 2★3.函数()()241--=-x x x e e f x x 的部分图象大致是★4.如图,在边长为2的正方形ABCD 中,其对称中心O 平分线段MN ,且2MN BC =,点E 为DC 的中点,则⋅=EM ENA . 12-B .32-C . -2D .-3★5.随着北京冬奥会的举办,中国冰雪运动的参与人数有了突飞猛进的提升。

某校为提升学生的综合素养、大力推广冰雪运动,号召青少年成为“三亿人参与冰雪运动的主力军”,开设了“陆地冰壶”“陆地冰球”“滑冰”“模拟滑雪”四类冰雪运动体验课程,甲、乙两名同学各自从中任意挑选两门课程学习,设事件A=“甲乙两人所选课程恰有一门相同”事件B=“甲乙两人所选课程完全不同”,事件C=“甲乙两人均未选择陆地冰壶课程”,则 A . A 与B 为对立事件 B .A 与C 互斥 C . B 与C 相互独立D . A 与C 相互独立★6.已知三棱锥P-ABC 中,PA ⊥平面ABC ,底面△ABC 是以B 为直角顶点的直角三角形,且23,π=∠=BC BCA ,三棱锥P-ABC的体积为3,过点A 作⊥AM PB 于M ,过M 作MN ⊥PC 于N ,则三棱锥P-AMN 外接球的体积为A .323π B.3C.3D .43π 7.若sin 2sin ,sin()tan()1αβαβαβ=+⋅-=,则tan tan αβ=A .2B .32C . 1D .128.已知函数f (x ),g (x )的定义域为R 。

专题04 恒成立问题(文理通用)(含详细答案)

专题04 恒成立问题(文理通用)(含详细答案)

专题04 恒成立问题一、单选题1.若定义在R 上的函数()f x 满足()()2f x f x -=+,且当1x <时,()x xf x e=,则满足()()35f f -的值 A .恒小于0 B .恒等于0 C .恒大于0D .无法判断2.()()(),f x R f x f x x R '∀∈设函数是定义在上的函数,其中的导函数为,满足对于()()f x f x '<恒成立,则下列各式恒成立的是A .2018(1)(0),(2018)(0)f ef f e f <<B .2018(1)(0),(2018)(0)f ef f e f >>C .2018(1)(0),(2018)(0)f ef f e f ><D .2018(1)(0),(2018)(0)f ef f ef3.已知0a >,0b >,下列说法错误的是 A .若1b a a b ⋅=,则2a b +≥ B .若23a b e a e b +=+,则a b > C .()ln ln a a b a b -≥-恒成立D .ln 0b ba a e+≥恒成立 4.若1x =是函数()4312*()1n n n f x a x a x a x n N ++=--+∈的极值点,数列{}n a 满足11a =,23a =,设31log n n b a +=,记[]x 表示不超过x 的最大整数.设12231202*********n n n S b b b b b b +⎡⎤=+++⎢⎥⎣⎦,若不等式n S t 对n +∀∈N 恒成立,则实数t 的最大值为 A .2020 B .2019 C .2018D .1010二、多选题1.若满足()()'0f x f x +>,对任意正实数a ,下面不等式恒成立的是 A .()()2f a f a < B .()()2af a ef a >-C .()()0>f a fD .()()0a f f a e>2.定义在R 上的函数()f x 的导函数为()f x ',且()()()f x xf x xf x '+<对x ∈R 恒成立,则下列选项不正确的是 A .2(2)(1)f f e> B .2(2)(1)f f e< C .()10f >D .()10f ->3.已知函数()cos sin f x x x x =-,下列结论中正确的是 A .函数()f x 在2x π=时,取得极小值1-B .对于[]0,x π∀∈,()0≤f x 恒成立C .若120x x π<<<,则1122sin sin x x x x < D .若sin x a b x <<,对于0,2x π⎛⎫∀∈ ⎪⎝⎭恒成立,则a 的最大值为2π,b 的最小值为14.已知函数()2f x x x=-,()()πcos 5202xg x a a a =+->,.给出下列四个命题,其中是真命题的为A .若[]1,2x ∃∈,使得()f x a <成立,则1a >-B .若R x ∀∈,使得()0g x >恒成立,则05a <<C .若[]11,2x ∀∈,2x ∀∈R ,使得()()12f x g x >恒成立,则6a >D .若[]11,2x ∀∈,[]20,1x ∃∈,使得()()12f x g x =成立,则34a ≤≤ 5.当1x >时,()41ln ln 3k x x x x --<-+恒成立,则整数k 的取值可以是 A .2- B .1- C .0D .16.下列不等式中恒成立的有 A .()ln 11xx x +≥+,1x >- B .11ln 2x x x ⎛⎫≤- ⎪⎝⎭,0x > C .1x e x ≥+ D .21cos 12x x ≥-1.函数3()2,()ln 1f x x x c g x x =-+=+,若()()f x g x ≥恒成立,则实数c 的取值范围是___________. 2.若[,)x e ∀∈+∞,满足32ln 0mxx x me -≥恒成立,则实数m 的取值范围为___________.3.已知函数()()21ax x xf x x ++=≥,若()0f x '≥恒成立,则a 的取值范围为___________.4.已知函数()ln f x x x =-,若()10f x m -+≤恒成立,则m 的取值范围为___________. 5.若函数()0x f x e ax =->恒成立,则实数a 的取值范围是___________.6.当[1,2]x ∈-时,32122x x x m --<恒成立,则实数m 的取值范围是___________. 7.若()()220xxx me exeex e ++-≤在()0,x ∈+∞上恒成立,则实数m 的取值范围为___________.8.已知函数()()(ln )xf x e ax x ax =--,若()0f x <恒成立,则a 的取值范围是___________.9.已知函数()1x f x e ax =+-,若0,()0x f x 恒成立,则a 的取值范围是___________.10.不等式()221n n n N *>-∈不是恒成立的,请你只对该不等式中的数字作适当调整,使得不等式恒成立,请写出其中一个恒成立的不等式:___________.11.已知()ln f x x x m x =--,若()0f x >恒成立,则实数m 的取值范围是___________.12.已知函数21,0()2,0x e x f x ax x x ⎧-≥=⎨+<⎩,若()1f x ax ≥-恒成立,则a 的取值范围是___________.13.函数()2cos sin f x x x x x =+-,当3,22x ππ⎡⎤∈⎢⎥⎣⎦时,()f x ax ≤恒成立,则实数a 的取值范围是___________. 14.已知0a <,且()221ln 0ax ax x ax -+≥+恒成立,则a 的值是___________.15.若对任意实数(],1x ∈-∞,2211xx ax e-+≥恒成立,则a =___________.1.已知函数()22ln f x ax x x =-+有两个不同的极值点1x ,2x ,则a 的取值范围___________;且不等式()()1212f x f x x x t +<++恒成立,则实数t 的取值范围___________.2.对任意正整数n ,函数32()27cos 1f n n n n n πλ=---,若(2)0f ≥,则λ的取值范围是___________;若不等式()0f n ≥恒成立,则λ的最大值为___________.3.已知函数1()ln (0)f x ax x a x=+>.(1)当1a =时,()f x 的极小值为___________;(2)若()f x ax ≥在(0,)+∞上恒成立,则实数a 的取值范围为___________. 4.已知函数()()221xf exx x =-+,则()f x 在点()()0,0f 处的切线方程为___________,若()f x ax ≥在()0,∞+上恒成立,则实数a 的取值范围为___________.5.设函数()32f x ax bx cx =++(a ,b ,R c ∈,0a ≠)若不等式()()2xf x af x '-≤对一切R x ∈恒成立,则a =___________,b ca+的取值范围为___________. 6.已知函数()()x x f x x ae e -=-为偶函数,函数()()xg x f x xe -=+,则a =___________;若()g x mx e >-对()0,x ∈+∞恒成立,则m 的取值范围为___________. 五、解答题1.已知函数()sin f x x ax =-,()=ln 1xg x x x e -+,2.71828e =⋅⋅⋅为自然对数的底数. (1)当()0,x π∈,()0f x <恒成立,求a 的取值范围;(2)当0a =时,记()()()h x f x g x =+,求证:对任意()1,x ∈+∞,()0h x <恒成立. 2.已知函数()1x f x ae x =--(1)若()0f x ≥对于任意的x 恒成立,求a 的取值范围 (2)证明:1111ln(1)23n n++++≥+对任意的n N +∈恒成立 3.若对任意的实数k 、b ,函数()y f x kx b =++与直线y kx b =+总相切,则称函数()f x 为“恒切函数”.(1)判断函数()2f x x =是否为“恒切函数”;(2)若函数()()ln 0f x m x nx m =+≠是“恒切函数”,求实数m 、n 满足的关系式;(3)若函数()()1x xf x e x e m =--+是“恒切函数”,求证:104m -<≤. 4.已知函数()(ln )sin x f x e x a x =+-.(1)若()ln sin f x x x ≥⋅恒成立,求实数a 的最大值; (2)若()0f x ≥恒成立,求正整数a 的最大值.专题04 恒成立问题一、单选题1.若定义在R 上的函数()f x 满足()()2f x f x -=+,且当1x <时,()x xf x e=,则满足()()35f f -的值 A .恒小于0 B .恒等于0 C .恒大于0D .无法判断【试题来源】安徽省皖江名校联盟2021届高三第二次联考(理) 【答案】C【分析】当1x <时,求导,得出导函数恒小于零,得出()f x 在(),1-∞内是增函数.再由()()2f x f x -=+得()f x 的图象关于直线1x =对称,从而得()f x 在()1,+∞内是减函数,由此可得选项.【解析】当1x <时,'1()0xx f x e -=->,则()f x 在(),1-∞内是增函数. 由()()2f x f x -=+得()f x 的图象关于直线1x =对称,所以()f x 在()1,+∞内是减函数, 所以()()350f f ->.故选C .2.()()(),f x R f x f x x R '∀∈设函数是定义在上的函数,其中的导函数为,满足对于()()f x f x '<恒成立,则下列各式恒成立的是A .2018(1)(0),(2018)(0)f ef f e f <<B .2018(1)(0),(2018)(0)f ef f e f >>C .2018(1)(0),(2018)(0)f ef f e f ><D .2018(1)(0),(2018)(0)f ef f ef【试题来源】2020届福建省仙游县枫亭中学高三上学期期中考试(理) 【答案】B【分析】构造函数()()xf x F x e =,求出'()0F x >,得到该函数为R 上的增函数,故得(0)(1)F F <,(0)(2018)F F <,从而可得到结论.【解析】设()()x f x F x e =,x R ∈(),所以'()()[]xf x F x e '==()()xf x f x e '-, 因为对于()(),x R f x f x ∀∈<',所以'()0F x >,所以()F x 是R 上的增函数,所以(0)(1)F F <,(0)(2018)F F <,即(1)(0)f f e <,2018(2018)(0)f f e <, 整理得()()10f ef >和()20182018(0f ef >).故故选B .3.已知0a >,0b >,下列说法错误的是 A .若1b a a b ⋅=,则2a b +≥ B .若23a b e a e b +=+,则a b > C .()ln ln a a b a b -≥-恒成立D .ln 0b ba a e+≥恒成立 【试题来源】浙江省杭州市萧山中学2019-2020学年高三下学期返校考试 【答案】D【解析】对于A ,不妨令01a <≤,1b ≥,则1aab bb a aa a ab a b a b ⎛⎫⎛⎫⋅=⋅=⋅= ⎪ ⎪⎝⎭⎝⎭,所以1baa b ⋅=即11b aaab-=,由10b a -≥可知101b aa -<≤,则101ab <≤,所以1≥ab ,2a b +≥,故A 正确; 对于B ,若a b ≤,则0a b e e -≤,320b a ->,故32ab e e b a -≠-即23a b e a e b +≠+,与已知矛盾,故B 正确;对于C ,()ln ln ln 1b b a a b a b a a-≥-⇔-≥-, 令0b x a =>,()()ln 10f x x x x =-->,则()1x f x x-'=, 则()f x 在()0,1上单调递减,在()1,+∞上单调递增, 所以()()10f x f ≥=,所以ln 10b b a a --≥即ln 1b ba a-≥-,故C 正确; 对于D ,设()()ln 0h x x x x =>,()()0x xg x x e=>, 则()ln 1h x x '=+,()1xxg x e -'=, 所以()h x 在()10,e -上单调递减,在()1,e -+∞上单调递增,则()()11h x h e e --≥=-,()g x 在()0,1上单调递增,在()1,+∞上单调递减,则()()11g x g e -≤=,所以()()110h e g e --+<,即当1a b e -==时ln 0bba a e +<,故D 错误.故选D . 4.若1x =是函数()4312*()1n n n f x a x a x a x n N ++=--+∈的极值点,数列{}n a 满足11a =,23a =,设31log n n b a +=,记[]x 表示不超过x 的最大整数.设12231202*********n n n S b b b b b b +⎡⎤=+++⎢⎥⎣⎦,若不等式n S t 对n +∀∈N 恒成立,则实数t 的最大值为 A .2020 B .2019 C .2018D .1010【试题来源】新疆维吾尔自治区2021届高三第二次联考数学(理)能力测试试题 【答案】D【分析】由极值点得数列的递推关系,由递推关系变形得数列1{}n n a a +-是等比数列,求得1n n a a +-,由累加法求得n a ,计算出n b ,然后求和122311202020202020n n b b b b b b ++++,利用增函数定义得此式的最小值,从而得出n S 的最小值,再由不等式恒成立可得t 的最大值. 【解析】3212()43n n n f x a x a x a '++=--,所以12(1)430n n n f a a a '++=--=, 即有()2113n n n n a a a a +++-=-,所以{}1n n a a +-是以2为首项3为公比的等比数列, 所以1123n n n a a -+-=⋅,1201111221123232313n n nn n n n n n n a a a a a a a a a a --++---=-+-+-++-+=⋅+⋅++⋅+=所以31log n n b a n +==,所以12231120202020202011120201223(1)n n b b b b b b n n +⎛⎫+++=+++⎪⨯⨯+⎝⎭1111120202020122311n n n n ⎛⎫=-+-++-=⎪++⎝⎭, 又20201ny n =+为增函数,当1n =时,1010n S =,10102020n S ≤<, 若n S t ≥恒成立,则t 的最大值为1010.故选D .【名师点睛】本题考查函数的极值,等比数列的判断与通项公式,累加法求通项公式,裂项相消法求和,函数新定义,不等式恒成立问题的综合应用.涉及知识点较多,属于中档题.解题方法是按部就班,按照题目提供的知识点顺序求解.由函数极值点得数列的递推公式,由递推公式引入新数列是等比数列,求得通项公式后用累加法求得n a ,由对数的概念求得n b ,用裂项相消法求和新数列的前n 项和,并利用函数单调性得出最小值,然后由新定义得n S 的最小值,从而根据不等式恒成立得结论. 二、多选题1.若满足()()'0f x f x +>,对任意正实数a ,下面不等式恒成立的是 A .()()2f a f a < B .()()2af a ef a >-C .()()0>f a fD .()()0af f a e>【试题来源】江苏省扬州中学2019-2020学年高二下学期6月月考 【答案】BD【分析】根据()()'0f x f x +>,设()()xh x e f x =,()()()()xh x ef x f x ''=+,得到()h x 在R 上是增函数,再根据a 是正实数,利用单调性逐项判断.【解析】设()()xh x e f x =,()()()()xh x ef x f x ''=+,因为()()'0f x f x +>,所以()0h x '>,()h x 在R 上是增函数, 因为a 是正实数,所以2a a <,所以()()22aae f a e f a <,因为21a a e e >>, ()(),2f a f a 大小不确定,故A 错误, 因为a a -<,所以()()aa ef a e f a --<,即()()2a f a e f a >-,故B 正确.因为0a >,所以()()()000a e f a e f f >=, 因为1a e >,()(),0f a f 大小不确定.故C 错误.()()()000a e f a e f f >=,因为1a e >,所以()()0af f a e>,故D 正确.故选BD. 【名师点睛】本题主要考查导数与函数单调性比较大小,还考查了运算求解的能力,属于中档题.2.定义在R 上的函数()f x 的导函数为()f x ',且()()()f x xf x xf x '+<对x ∈R 恒成立,则下列选项不正确的是 A .2(2)(1)f f e> B .2(2)(1)f f e< C .()10f >D .()10f ->【试题来源】江苏省盐城市伍佑中学2019-2020学年高二下学期期中 【答案】BCD【分析】构造出函数()()xxf x F x e =,再运用求导法则求出其导数,借助导数与函数单调性之间的关系及题设中()()()f x xf x xf x '+<,从而确定函数()()xxf x F x e =是单调递减函数,然后可判断出每个答案的正误. 【解析】构造函数()()xxf x F x e =, 因为2[()()]()()()()()0()x x x xe f x xf x xe f x f x xf x xf x F x e e '+-+-=='<', 故函数()()xxf x F x e=在R 上单调递减函数, 因为21>,所以212(2)(1)(2)(1)f f F F e e <⇒<,即2(2)(1)f f e<,故A 正确,B 错误; 因为()(1)0F F <,即()10f e<,所以()10f <,故C 错误; 因为()(1)0F F ->,即()110f e--->,所以()10f -<,故D 错误,故选BCD. 【名师点睛】解答本题的难点所在是如何依据题设条件构造出符合条件的函数()()xxf x F x e=,这里要求解题者具有较深的观察力和扎实的基本功,属于较难题. 3.已知函数()cos sin f x x x x =-,下列结论中正确的是 A .函数()f x 在2x π=时,取得极小值1-B .对于[]0,x π∀∈,()0≤f x 恒成立C .若120x x π<<<,则1122sin sin x x x x < D .若sin x a b x <<,对于0,2x π⎛⎫∀∈ ⎪⎝⎭恒成立,则a 的最大值为2π,b 的最小值为1【试题来源】山东省肥城市2019-2020学年高二下学期期中考试 【答案】BCD【分析】先对函数求导,根据022f ππ⎛⎫'=-≠⎪⎝⎭,排除A ;再由导数的方法研究函数单调性,判断出B 选项;构造函数()sin xg x x=,由导数的方法研究其单调性,即可判断C 选项;根据()sin x g x x =的单调性,先得到sin 2x x π>,再令()sin h x x x =-,根据导数的方法研究其单调性,得到sin 1xx<,即可判断D 选项. 【解析】因为()cos sin f x x x x =-,所以()cos sin cos sin f x x x x x x x '=--=-, 所以022f ππ⎛⎫'=-≠⎪⎝⎭,所以2x π=不是函数的极值点,故A 错; 若[]0,x π∈,则()sin 0f x x x '=-≤,所以函数()cos sin f x x x x =-在区间[]0,π上单调递减;因此()()00≤=f x f ,故B 正确; 令()sin x g x x =,则()2cos sin x x x g x x -'=, 因为()cos sin 0f x x x x =-≤在[]0,π上恒成立,所以()2cos sin 0x x xg x x -'=<在()0,π上恒成立,因此函数()sin xg x x=在()0,π上单调递减;又120x x π<<<,所以()()12g x g x >,即1212sin sin x x x x >,所以1122sin sin x x x x <,故C 正确;因为函数()sin x g x x =在()0,π上单调递减;所以0,2x π⎛⎫∈ ⎪⎝⎭时,函数()sin x g x x =也单调递减,因此()sin 22x g x g x ππ⎛⎫=>= ⎪⎝⎭在0,2π⎛⎫⎪⎝⎭上恒成立;令()sin h x x x =-,0,2x π⎛⎫∈ ⎪⎝⎭,则()1cos 0h x x '=-≥在0,2π⎛⎫⎪⎝⎭上恒成立,所以()sin h x x x =-在0,2π⎛⎫⎪⎝⎭上单调递增, 因此()sin 0h x x x =->,即sin 1xx <在0,2π⎛⎫ ⎪⎝⎭上恒成立; 综上,2sin 1x x π<<在0,2π⎛⎫⎪⎝⎭上恒成立,故D 正确.故选BCD . 【名师点睛】本题主要考查导数的应用,利用导数的方法研究函数的极值,单调性等,属于常考题型.4.已知函数()2f x x x=-,()()πcos 5202xg x a a a =+->,.给出下列四个命题,其中是真命题的为A .若[]1,2x ∃∈,使得()f x a <成立,则1a >-B .若R x ∀∈,使得()0g x >恒成立,则05a <<C .若[]11,2x ∀∈,2x ∀∈R ,使得()()12f x g x >恒成立,则6a >D .若[]11,2x ∀∈,[]20,1x ∃∈,使得()()12f x g x =成立,则34a ≤≤ 【试题来源】冲刺2020高考数学之拿高分题目强化卷(山东专版) 【答案】ACD【分析】对选项A ,()f x 在[]1,2上的最小值小于a 即可;对选项B ,()g x 的最小值大于0即可;对选项C ,()f x 在[]1,2上的最小值大于()g x 的最大值即可;对选项D ,[]11,2x ∀∈,[]20,1x ∃∈,()min min ()g x f x ≤,()max max ()g x f x ≥即可.【解析】对选项A ,只需()f x 在[]1,2上的最小值小于a ,()f x 在[]1,2上单调递增,所以min 2()(1)111f x f ==-=-,所以1a >-,故正确; 对选项B ,只需()g x 的最小值大于0,因为[]πcos,2x a a a∈-,所以min ()52530g x a a a =-+-=->,所以503a <<,故错误; 对选项C ,只需()f x 在[]1,2上的最小值大于()g x 的最大值,min ()1f x =-,max ()525g x a a a =+-=-,即15a ->-,6a >,故正确;对选项D ,只需()min min ()g x f x ≤,()max max ()g x f x ≥,max 2()(2)212f x f ==-=,所以[]11,2x ∈,[]1()1,1f x ∈-, []0,1x ∈时,π0,22x π⎡⎤∈⎢⎥⎣⎦,所以()g x 在[]0,1上单调递减, ()min (1)52a g x g ==-,()max (0)5a g x g ==-,所以()[]52,5g x a a ∈--,由题意,52151a a -≤-⎧⎨-≥⎩⇒34a ≤≤,故正确.故选ACD .【名师点睛】本题主要考查不等式恒成立和存在性问题,考查学生的分析转化能力,注意恒成立问题和存在性问题条件的转化,属于中档题.5.当1x >时,()41ln ln 3k x x x x --<-+恒成立,则整数k 的取值可以是 A .2- B .1- C .0D .1【试题来源】江苏省南京市2020-2021学年高三上学期期中考前训练 【答案】ABC 【分析】将()41ln ln 3k x x x x --<-+,当1x >时,恒成立,转化为13ln ln 4x k x x x ⎛⎫<++ ⎪⎝⎭,当1x >时,恒成立,令()()3ln ln 1x F x x x x x =++>,利用导数法研究其最小值即可.【解析】因为当1x >时,()41ln ln 3k x x x x --<-+恒成立, 所以13ln ln 4x k x x x ⎛⎫<++ ⎪⎝⎭,当1x >时,恒成立, 令()()3ln ln 1xF x x x x x =++>,则()222131ln 2ln x x x F x x x x x---'=-+=.令()ln 2x x x ϕ=--,因为()10x x xϕ-'=>,所以()x ϕ在()1,+∞上单调递增. 因为()10ϕ<,所以()0F x '=在()1,+∞上有且仅有一个实数根0x , 于是()F x 在()01,x 上单调递减,在()0,x +∞上单调递增, 所以()()000min 00ln 3ln x F x F x x x x ==++.(*) 因为()1ln 3309F -'=<,()()21ln 22ln 4401616F --'==>,所以()03,4x ∈,且002ln 0x x --=,将00ln 2x x =-代入(*)式, 得()()0000min 00023121x F x F x x x x x x -==-++=+-,()03,4x ∈. 因为0011t x x =+-在()3,4上为增函数,所以713,34t ⎛⎫∈ ⎪⎝⎭,即()min1713,41216F x ⎛⎫∈ ⎪⎝⎭. 因为k 为整数,所以0k ≤.故选ABC . 6.下列不等式中恒成立的有 A .()ln 11xx x +≥+,1x >- B .11ln 2x x x ⎛⎫≤- ⎪⎝⎭,0x > C .1x e x ≥+D .21cos 12x x ≥-【试题来源】广东省中山市2019-2020学年高二下学期期末 【答案】ACD 【分析】令10tx ,()1ln 1f t t t=+-,导数方法求出最小值,即可判定出A 正确;令()11ln 2f x x x x ⎛⎫=-- ⎪⎝⎭,0x >,导数方法研究单调性,求出范围,即可判定B 错; 令()1xf x e x =--,导数的方法求出最小值,即可判定C 正确;令()21cos 12f x x x =-+,导数的方法求出最小值,即可判定D 正确. 【解析】A 选项,因为1x >-,令10t x ,()1ln 1f t t t=+-,则()22111t f t t t t -'=-=,所以01t <<时,()210t f t t-'=<,即()f t 单调递减;1t >时,()210t f t t -'=>,即()f t 单调递增; 所以()()min 10f t f ==,即()1ln 10f t t t=+-≥,即1ln t t t -≥,即()ln 11x x x +≥+,1x >-恒成立;故A 正确;B 选项,令()11ln 2f x x x x ⎛⎫=-- ⎪⎝⎭,0x >, 则()()2222211112110222x x x f x x x x x ---⎛⎫'=-+==-≤ ⎪⎝⎭显然恒成立, 所以()11ln 2f x x x x ⎛⎫=-- ⎪⎝⎭在0x >上单调递减, 又()10f =,所以当()0,1x ∈时,()()10f x f >=,即11ln 2x x x ⎛⎫>- ⎪⎝⎭,故B 错; C 选项,令()1xf x e x =--,则()1xf x e '=-,当0x >时,()10xf e x ='->,即()f x 单调递增;当0x <时,()10xf e x ='-<,所以()f x 单调递减;则()()00f x f ≥=,即1x e x ≥+恒成立;故C 正确; D 选项,令()21cos 12f x x x =-+,则()sin f x x x '=-+, 所以()cos 10f x x ''=-+≥恒成立,即函数()sin f x x x '=-+单调递增, 又()00f '=,所以当0x >时,()0f x '>,即()21cos 12f x x x =-+单调递增; 当0x <时,()0f x '<,即()21cos 12f x x x =-+单调递减; 所以()()min 00f x f ==,因此21cos 12x x ≥-恒成立,故D 正确;故选ACD . 三、填空题1.函数3()2,()ln 1f x x x c g x x =-+=+,若()()f x g x ≥恒成立,则实数c 的取值范围是___________.【试题来源】【全国区级联考】江苏省徐州市铜山区下学期高二数学(文)期中试题 【答案】2c ≥【解析】由()()f x g x ≥,即32ln 1x x c x -+≥+,即32ln 1c x x x ≥-+++.令()()32ln 10h x x x x x =-+++>,()()()21331x x x h x x'-++=-,故函数()h x 在区间()0,1上递增,在()1,+∞上递减,最大值为()12h =,所以2c ≥.【名师点睛】本题主要考查利用分析法和综合法求解不等式恒成立,问题,考查利用导数研究函数的单调性,极值和最值等知识.首先根据()()f x g x ≥,对函数进行分离常数,这里主要的思想方法是分离常数后利用导数求得另一个部分的最值,根据这个最值来求得参数的取值范围.2.若[,)x e ∀∈+∞,满足32ln 0mxx x me -≥恒成立,则实数m 的取值范围为___________.【试题来源】2020届湖南省长沙市长郡中学高三下学期3月停课不停学阶段性测试(理) 【答案】(,2]e -∞【分析】首先对参数的范围进行讨论,分两种情况,尤其是当0m >时,对式子进行变形,构造新函数,将恒成立问题转化为最值来处理,利用函数的单调性来解决,综述求得最后的结果.【解析】(1)0m ≤,显然成立;(2)0m >时,由32ln 0mxx x me -≥22ln m x m x x e x ⇒≥2ln (2ln )mxx m x e e x⇒≥,由()x f x xe =在[),e +∞为增2ln mx x⇒≥2ln m x x ⇒≤在[),e +∞恒成立, 由()2ln g x x x =在[),e +∞为增,min ()2g x e =,02m e <≤, 综上,2m e ≤,故答案为(,2]e -∞.3.已知函数()()21ax x xf x x ++=≥,若()0f x '≥恒成立,则a 的取值范围为___________.【试题来源】四川省泸州市2020学年下学期高二期末统一考试(文) 【答案】(],3-∞【分析】求函数的导数,根据()0f x ',利用参数分离法进行转化,然后构造函数()g x ,转化为求函数的最值即可.【解析】函数的导数2()21f ax x x '=+-,由()0f x '在1x 上恒成立得2210a x x +-在1x 上恒成立,即221a x x+,得322x x a +在1x 上恒成立,设32()2g x x x =+, 则2()622(31)g x x x x x '=+=+,当1x 时,()0g x '>恒成立,即()g x 在1x 上是增函数, 则当1x =时,()g x 取得最小值()1213g =+=,则3a , 即实数a 的取值范围是(],3-∞,故答案为(],3-∞.【名师点睛】本题主要考查函数恒成立问题,求函数的导数,利用参数分离法以及构造函数,利用导数研究函数的最值是解决本题的关键.属于中档题.4.已知函数()ln f x x x =-,若()10f x m -+≤恒成立,则m 的取值范围为___________. 【试题来源】2020年高考数学选填题专项测试(文理通用) 【答案】[)0,+∞【分析】把()ln f x x x =-,代入()10f x m -+≤,即ln 1m x x ≥-+恒成立,构造()ln 1g x x x =-+,利用导数研究最值,即得解.【解析】()ln f x x x =-,则()10f x m -+≤恒成立,等价于ln 1m x x ≥-+令11()ln 1(0),'()1(0)x g x x x x g x x x x-=-+>=-=> 因此()g x 在(0,1)单调递增,在(1)+∞,单调递减, 故max ()(1)00g x g m ==∴≥,故答案为[)0,+∞.【名师点睛】本题考查了导数在不等式的恒成立问题中的应用,考查了学生转化与划归,数学运算的能力,属于中档题.5.若函数()0x f x e ax =->恒成立,则实数a 的取值范围是___________. 【试题来源】2020届四川省成都七中高三二诊数学模拟(理)试题 【答案】0a e ≤<【分析】若函数()0x f x e ax =->恒成立,即min ()0f x >,求导得'()x f x e a =-,在0,0,0a a a >=<三种情况下,分别讨论函数单调性,求出每种情况时的min ()f x ,解关于a的不等式,再取并集,即得.【解析】由题意得,只要min ()0f x >即可,'()x f x e a =-,当0a >时,令'()0f x =解得ln x a =,令'()0f x <,解得ln x a <,()f x 单调递减, 令'()0f x >,解得ln x a >,()f x 单调递增,故()f x 在ln x a =时,()f x 有最小值,min ()(ln )(1ln )f x f a a a ==-, 若()0f x >恒成立,则(1ln )0a a ->,解得0a e <<; 当0a =时,()0x f x e =>恒成立; 当0a <时,'()x f x e a =-,()f x 单调递增,,()x f x →-∞→-∞,不合题意,舍去.综上,实数a 的取值范围是0a e ≤<.故答案为0a e ≤<6.当[1,2]x ∈-时,32122x x x m --<恒成立,则实数m 的取值范围是___________. 【试题来源】陕西省商洛市洛南中学2019-2020学年高二下学期第二次月考(理) 【答案】(2,)+∞【分析】设()3212,[1,2]2x x x x f x --∈-=,利用导数求得函数的单调性与最大值,结合题意,即可求得实数m 的取值范围.【解析】由题意,设()3212,[1,2]2x x x x f x --∈-=, 则()22(1)(323)x x f x x x --=-+'=,当2[1,)3x ∈--或(1,2]x ∈时,()0f x '>,()f x 单调递增;当2(,1)3x ∈-时,()0f x '<,()f x 单调递减, 又由222(),(2)2327f f -==,即2()(2)3f f -<, 即函数()f x 在区间[1,2]-的最大值为2,又由当[1,2]x ∈-时,32122x x x m --<恒成立,所以2m >, 即实数m 的取值范围是(2,)+∞.故答案为(2,)+∞【名师点睛】本题主要考查了恒成立问题的求解,其中解答中熟练应用函数的导数求得函数的单调性与最值是解答的关键,着重考查推理与运算能力,属于基础题.7.若()()220xxx me exeex e ++-≤在()0,x ∈+∞上恒成立,则实数m 的取值范围为___________.【试题来源】浙江省杭州地区(含周边)重点中学2020-2021学年高三上学期期中 【答案】32m ≤-【分析】对已知不等式进行变形,利用换元法、构造函数法、常变量分离法,结合导数的性质进行求解即可.【解析】()()()()222210xx x x x xme ex e ex me ex e ex e e++++-⇒≤≤ (1), 令x ext e=,因为()0,x ∈+∞,所以0t >, 则不等式(1)化为2221(2)(1)11t t m t t m t --+++≤⇒≤+,设()xex f x e=,()0,x ∈+∞,'(1)()x e x f x e -=,当1x >时,'()0,()f x f x <单调递减, 当01x <<时,'()0,()f x f x >单调递增,因此当()0,x ∈+∞时,max ()(1)1f x f ==, 而(0)0f =,因此当()0,x ∈+∞时,()(0,1]f x ∈,因此(0,1]t ∈,设2221()1t t g t t --+=+,(0,1]t ∈,因此要想()()220x x xme ex e ex e ++-≤在()0,x ∈+∞上恒成立,只需min ()m g t ≤,2'2243()(1)t t g t t ---=+,因为(0,1]t ∈,所以'()0g t <,因此()g t 在(0,1]t ∈时单调递减,所以min 3()(1)2g t g ==-,因此32m ≤-.8.已知函数()()(ln )xf x e ax x ax =--,若()0f x <恒成立,则a 的取值范围是___________.【试题来源】四川省三台中学实验学校2019-2020学年高二下学期期末适应性考试(理) 【答案】1,e e ⎛⎫ ⎪⎝⎭【分析】先由x y e =的图象与ln y x =的图象可得,ln >x e x 恒成立;原问题即可转化为直线y ax =介于x y e =与ln y x =之间,作出其大致图象,由图象得到只需<<OA OB k a k ;根据导数的方法求出OA ,OB 所在直线斜率,进而可得出结果. 【解析】由x y e =的图象与ln y x =的图象可得,ln >x e x 恒成立;所以若()()(ln )0=--<xf x e ax x ax 恒成立,只需0ln 0x e ax x ax ⎧->⎨-<⎩,即直线y ax =介于x y e =与ln y x =之间,作出其大致图象如下:由图象可得,只需<<OA OB k a k ;设11(,)A x y ,由ln y x =得1y x'=,所以111OA x x k y x =='=, 所以曲线ln y x =在点11(,)A x y 处的切线OA 的方程为1111ln ()-=-y x x x x , 又该切线过点O ,所以11110ln (0)1-=-=-x x x ,解得1x e =,所以1=OA k e; 设22(,)B x y ,由x y e =得e x y '=,所以22x OB x x k y e =='=,所以曲线x y e =在点22(,)B x y 处的切线OB 的方程为222()-=-x x y e e x x ,又该切线过点O ,所以2220(0)-=-x x ee x ,解得21x =,所以=OB k e ;所以1a e e <<.故答案为1,e e ⎛⎫⎪⎝⎭. 【名师点睛】本题主要考查由导数的方法研究不等式恒成立的问题,熟记导数的几何意义即可,属于常考题型.9.已知函数()1x f x e ax =+-,若0,()0x f x 恒成立,则a 的取值范围是___________. 【试题来源】黑龙江省七台河市田家炳高级中学2019-2020学年高二下学期期中考试(理)【答案】[1,)-+∞【分析】求导得到()x f x e a '=+,讨论10a +和10a +<两种情况,计算10a +<时,函数()f x 在[)00,x 上单调递减,故()(0)0f x f =,不符合,排除,得到答案. 【解析】因为()1x f x e ax =+-,所以()x f x e a '=+,因为0x ,所以()1f x a '+. 当10a +,即1a ≥-时,()0f x ',则()f x 在[0,)+∞上单调递增,从而()(0)0f x f =,故1a ≥-符合题意;当10a +<,即1a <-时,因为()x f x e a '=+在[0,)+∞上单调递增,且(0)10f a '=+<,所以存在唯一的0(0,)x ∈+∞,使得()00f x '=.令()0f x '<,得00x x <,则()f x 在[)00,x 上单调递减,从而()(0)0f x f =,故1a <-不符合题意.综上,a 的取值范围是[1,)-+∞.故答案为[1,)-+∞.10.不等式()221n n n N *>-∈不是恒成立的,请你只对该不等式中的数字作适当调整,使得不等式恒成立,请写出其中一个恒成立的不等式:___________. 【试题来源】北京市101中学2019-2020学年高三10月月考 【答案】331n n >-【分析】将不等式中的数字2变为3,得出331n n >-,然后利用导数证明出当3n ≥时,33n n ≥即可,即可得出不等式331n n >-对任意的n *∈N 恒成立.【解析】13311>-,23321>-,33331>-,猜想,对任意的n *∈N ,331n n >-.下面利用导数证明出当3n ≥时,33n n ≥,即证ln 33ln n n ≥,即证ln ln 33n n ≤, 构造函数()ln x f x x =,则()21ln xf x x -'=,当3x ≥时,()0f x '<. 所以,函数()ln x f x x =在区间[)3,+∞上单调递减,当3n ≥时,ln ln 33n n ≤.所以,当3n ≥且n *∈N 时,33n n ≥,所以,331n n >-.故答案为331n n >-. 【名师点睛】本题考查数列不等式的证明,考查了归纳法,同时也考查了导数在证明数列不等式的应用,考查推理能力,属于中等题.11.已知()ln f x x x m x =--,若()0f x >恒成立,则实数m 的取值范围是___________. 【试题来源】湖北省襄阳市第一中学2019-2020学年高二下学期5月月考 【答案】(,1)-∞【分析】函数()f x 的定义域为(0,)x ∈+∞,由()0f x >,得ln ||xx m x->,分类讨论,分离参数,求最值,即可求实数m 的取值范围.【解析】函数()f x 的定义域为(0,)x ∈+∞,由()0f x >,得ln ||xx m x->, (ⅰ)当(0,1)x ∈时,||0x m -≥,ln 0xx<,不等式恒成立,所以m R ∈; (ⅰ)当1x =时,|1|0m -≥,ln 0xx=,所以1m ≠; (ⅰ)当1x >时,不等式恒成立等价于ln x m x x <-恒成立或ln xm x x>+恒成立, 令ln ()x h x x x =-,则221ln ()x x h x x'-+=,因为1x >,所以()0h x '>,从而()1h x >, 因为ln xm x x<-恒成立等价于min ()m h x <,所以1m , 令ln ()x g x x x =+,则221ln ()x xg x x+-'=, 再令2()1ln p x x x =+-,则1'()20p x x x=->在(1,)x ∈+∞上恒成立,()p x 在(1,)x ∈+∞上无最大值,综上所述,满足条件的m 的取值范围是(,1)-∞.故答案为(,1)-∞.12.已知函数21,0()2,0x e x f x ax x x ⎧-≥=⎨+<⎩,若()1f x ax ≥-恒成立,则a 的取值范围是___________.【试题来源】陕西省安康市2020-2021学年高三上学期10月联考(理)【答案】4e -⎡⎤⎣⎦【分析】若()1f x ax ≥-,则211,021,0x e ax x ax x ax x ⎧-≥-≥⎨+≥-<⎩,当0x =时,显然成立,当0x ≠时,则2,021,0xe a x xx a x x x ⎧≤>⎪⎪⎨+⎪≥<⎪-⎩,然后构造函数()x e g x x=(0x >),()221x h x x x +=-(0x <),分别求解函数()g x 的最小值和()h x 的最大值,只需()()min max h x a g x ≤≤即可.【解析】若()1f x ax ≥-,则211,021,0x e ax x ax x ax x ⎧-≥-≥⎨+≥-<⎩,当0x =时,显然成立;当0x ≠时,则()2,012,0x e ax x a x x x x ⎧≥>⎪⎨-≥--<⎪⎩,因为当0x <时,20x x ->, 所以只需满足2,021,0xe a x xx a x x x ⎧≤>⎪⎪⎨+⎪≥<⎪-⎩即可,令()x e g x x =(0x >),则()()21x x e g x x-'=, 则()0,1x ∈时,()0g x '<,所以()g x 在()0,1x ∈上递减, 当()1,x ∈+∞时,()0g x '>,则()g x 在()1,+∞上递增, 所以()()1min g x g e ==,所以a e ≤,令()221x h x x x +=-(0x <), 则()()()()()()22222222112221x x x x x x h x x x x x --+-+-'==--,令()0h x '=,得x =x =则当x ⎛∈-∞ ⎝ ⎭时,()0h x '>;当x ⎫∈⎪⎪⎝⎭时,()0h x '<, 所以函数()h x在⎛-∞ ⎝ ⎭上递增,在⎫⎪⎪⎝⎭上递减, 所以()4maxh x h ===-⎝⎭⎝⎭故4a ≥-4a e -≤.故答案为4e -⎡⎤⎣⎦.【名师点睛】本题考查根据不等式恒成立问题求参数的取值范围问题,考查学生分析问题、转化问题的能力,考查参变分离思想的运用,考查利用导数求解函数的最值,属于难题. 解决此类问题的方法一般有以下几种:(1)作出函数的图象,利用数形结合思想加以研究;(2)先进行参变分离,然后利用导数研究函数的最值,即可解决问题,必要时可以构造新函数进行研究.13.函数()2cos sin f x x x x x =+-,当3,22x ππ⎡⎤∈⎢⎥⎣⎦时,()f x ax ≤恒成立,则实数a 的取值范围是___________.【试题来源】河南省名校联盟2020届高三(6月份)高考数学(理)联考试题 【答案】[)0,+∞ 【分析】先根据2x π=时22f a ππ⎛⎫≤⎪⎝⎭得0a ≥,再对函数()f x 求导,研究导函数的单调性、最值等,进而研究函数()f x 单调性,即可解决.【解析】22f a ππ⎛⎫≤ ⎪⎝⎭,02f ⎛⎫= ⎪⎝⎭π,0a ∴≥. 由题意得()()2sin sin cos 1sin cos 1f x x x x x x x x '=-++-=-+-⎡⎤⎣⎦, 令()sin cos 1g x x x x =-+-,则()sin g x x x '=-. 当,2x π⎛⎤∈π⎥⎝⎦时,()0g x '<,()g x 单调递减; 当3,2x ππ⎛⎫∈ ⎪⎝⎭时,()0g x '>,()g x 单调递增,()g x ∴的最小值为()1g ππ=--. 又22g π⎛⎫=- ⎪⎝⎭,302g π⎛⎫= ⎪⎝⎭,3,22x ππ⎡⎤∴∈⎢⎥⎣⎦,()0g x ≤,即()0f x '≤, ()f x ∴在区间3,22ππ⎡⎤⎢⎥⎣⎦为减函数.02f π⎛⎫= ⎪⎝⎭,∴当3,22x ππ⎡⎤∈⎢⎥⎣⎦时,()0f x ≤.又当0a ≥,3,22x ππ⎡⎤∈⎢⎥⎣⎦时,0ax ≥,故()f x ax ≤恒成立,因此a 的取值范围是[)0,+∞.14.已知0a <,且()221ln 0ax ax x ax -+≥+恒成立,则a 的值是___________.【试题来源】6月大数据精选模拟卷04(上海卷)(满分冲刺篇) 【答案】e -【分析】把不等式()221ln 0a x ax x ax -+≥+恒成立,转化为函数()()()1ln 0f x ax ax x =+⋅-≥在定义域内对任意的x 恒成立,结合函数的单调性和零点,得出1a-是函数ln y ax x =-的零点,即可求解. 【解析】由题意,不等式()221ln 0a x ax x ax -+≥+恒成立,即函数()()()1ln 0f x ax ax x =+⋅-≥在定义域内对任意的x 恒成立,由ln ,0,0y ax x a x =-<>,则10y a x'=-<,所以ln y ax x =-为(0,)+∞减函数, 又由当0a <,可得1y ax =+为(0,)+∞减函数, 所以1y ax =+ 与ln y ax x =-同为单调减函数,且1a-是函数1y ax =+的零点, 故1a -是函数ln y ax x =-的零点,故110ln a a a ⎛⎫⎛⎫=⋅--- ⎪ ⎪⎝⎭⎝⎭,解得a e =-.【名师点睛】本题主要考查了不等式的恒成立问题,以及函数与方程的综合应用,其中解答中把不等式恒成立问题转化为函数的性质和函数的零点问题是解答的关键,着重考查转化思想,以及推理与运算能力.15.若对任意实数(],1x ∈-∞,2211xx ax e-+≥恒成立,则a =___________. 【试题来源】2020届辽宁省抚顺市高三二模考试(理) 【答案】12-【分析】设()()2211xx ax f x x e-+=≤,结合导数可知当0a <时,()()min 21f x f a =+;由题意可知,()()2122211a a f x f a e++≥+=≥,设()1t g t e t =--,则()0g t ≤,由导数可求出当0t =时,()g t 有最小值0,即()0g t ≥.从而可确定()0g t =,即可求出a 的值.【解析】设()()2211xx ax f x x e -+=≤,则()()()121xx x a f x e --+⎡⎤⎣⎦'=.当211a +≥,即0a ≥时,()0f x '≤,则()f x 在(],1-∞上单调递减, 故()()2211a f x f e -≥=≥,解得102ea ≤-<,所以0a ≥不符合题意; 当211a +<,即0a <时,()f x 在(),21a -∞+上单调递减,在(]21,1a +上单调递增, 则()()min21f x f a =+.因为2211xx ax e -+≥,所以()()2122211a a f x f a e ++≥+=≥. 令211a t +=<,不等式21221a a e++≥可转化为10te t --≤,设()1t g t e t =--, 则()1tg t e '=-,令()0g t '<,得0t <;令()0g t '>,得01t <<,则()g t 在(),0-∞上单调递减,在()0,1上单调递增;当0t =时,()g t 有最小值0, 即()0g t ≥.因为()0g t ≤,所以()0g t =,此时210a +=,故12a =-. 【名师点睛】本题考查了函数最值的求解,考查了不等式恒成立问题.本题的难点在于将已知恒成立问题,转化为()10tg t e t =--≤恒成立.本题的关键是结合导数,对含参、不含参函数最值的求解. 四、双空题1.已知函数()22ln f x ax x x =-+有两个不同的极值点1x ,2x ,则a 的取值范围___________;且不等式()()1212f x f x x x t +<++恒成立,则实数t 的取值范围___________.【试题来源】辽宁省锦州市渤大附中、育明高中2020-2021学年高三上学期第一次联考 【答案】10,2⎛⎫ ⎪⎝⎭[)5,-+∞【分析】求出导函数()2122122ax x f x ax x x-+'=-+=,只需方程22210ax x -+=有两个不相等的正根,满足1212010210x x a x x a ⎧⎪∆>⎪⎪=>⎨⎪⎪+=>⎪⎩,解不等式组可得a 的取值范围;求出 ()()1212f x f x x x +--的表达式,最后利用导数,通过构造函数,求出新构造函数的单调性,最后求出t 的取值范围.【解析】2221()(0)ax x f x x x'-+=>,因为函数()22ln f x ax x x =-+有两个不同的极值点12,x x ,所以方程22210ax x -+=有两个不相等的正实数根,于是有:121248010102a x x a x x a ⎧⎪∆=->⎪⎪+=>⎨⎪⎪=>⎪⎩,解得102a <<.()()221112221212122ln 2ln f x f x x x x ax x x ax x x x +--+--++=--()()212121212()23ln a x x x x x x x x ⎡⎤=+--++⎣⎦21ln 2a a=---, 设21()1ln 2,02h a a a a ⎛⎫=---<< ⎪⎝⎭, 22()0a h a a '-=>,故()h a 在102a <<上单调递增,故1()52h a h ⎛⎫<=-⎪⎝⎭,所以5t ≥-.因此t 的取值范围是[)5,-+∞. 故答案为10,2⎛⎫ ⎪⎝⎭;[)5,-+∞【名师点睛】本题考查了已知函数极值情况求参数取值范围问题,考查了不等式恒成立问题,构造新函数,利用导数是解题的关键,属于基础题.2.对任意正整数n ,函数32()27cos 1f n n n n n πλ=---,若(2)0f ≥,则λ的取值范围是___________;若不等式()0f n ≥恒成立,则λ的最大值为___________. 【试题来源】2021年新高考数学一轮复习学与练 【答案】13,2⎛⎤-∞-⎥⎝⎦132-【分析】将2n =代入求解即可;当n 为奇数时,cos 1n π=-,则转化。

湖南省长沙市英才大联考长郡中学2023-2024学年高三上学期月考卷(二)化学试题+Word版含答案

湖南省长沙市英才大联考长郡中学2023-2024学年高三上学期月考卷(二)化学试题+Word版含答案

英才大联考长郡中学2024届高三月考试卷(二)化学得分:_________本试题卷分选择题和非选择题两部分,共8页.时量75分钟,满分100分. 可能用到的相对原子质量:H ~1 Li ~7 C ~12 N ~14 O ~16 Na ~23一、选择题(本题共14小题,每小题3分,共42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.我国航天技术的进步离不开新技术和新材料的应用.下列说法正确的是( ) A .飞船建造通常用镁、铝、钛等合金,合金的熔点一定比各成分金属低 B .火箭使用碳纳米管可以减轻火箭质量,这种材料属于有机高分子材料 C .飞船船体覆盖的耐高温陶瓷材料属于新型无机非金属材料 D .太阳能电池翼伸展机构关键部件用到的SiC 属于硅酸盐材料 2.下列化学用语不正确的是( ) A .中子数为2的氢核素:3HB .用电子式表示H 2O 的形成过程:H +O +H H O H ::→⋅⋅⋅⋅C .基态铬原子的价电子排布式:3d 44s²D .23CO -的空间结构模型:3.下列说法正确的是( )A .向硫酸铜溶液中加入过量氨水,最终没有沉淀生成,说明反应前后2Cu +浓度未改变 B .将SOCl 2与32AlCl 6H O ⋅混合并加热,可制得无水AlCl 3C .酰胺在酸或碱存在并加热的条件下都可以发生水解反应且均有氨气逸出D .邻羟基苯甲醛的沸点比对羟基苯甲醛的沸点高4.布洛芬是一种常用于退烧镇痛的药物,合成路线如图所示.下列有关说法错误的是( )A .物质A 中所有碳原子可能共平面B .物质B 能使酸性高锰酸钾溶液褪色C .布洛芬能发生取代反应、加成反应、氧化反应D .布洛芬分子存在对映异构体5.下列反应的离子方程式正确的是( )A .向23Na SO 溶液中滴加稀3HNO 溶液:2322SO 2H SO H O -++↑+B .向()32Ca HCO 溶液中加入过量澄清石灰水:223323Ca 2HCO 2OH CaCO 2H O CO +---++↓++ C .向2100mL0.1mol /LFeBr 溶液中通入2224mLCl :23222Fe 2Br 2Cl 2Fe Br 4Cl +-+-++++D .常温下Cl 2通入NaOH 溶液中转化为2种盐:222OH Cl Cl ClO H O ---+++6.1-溴丁烷是密度比水大、难溶于水的无色液体,常用作有机合成的烷基化试剂.将浓硫酸、NaBr 固体、l -丁醇混合加热回流后,再经洗涤→干燥→蒸馏获得纯品.实验中涉及如下装置(部分夹持和加热装置省略):下列说法错误的是( )A .加热回流时,浓硫酸的作用是作反应物、催化剂等B .气体吸收装置的作用是吸收HBr 等有毒气体C .蒸馏装置中为了增强冷凝效果,可将直形冷凝管替换成球形冷凝管D .分液操作时,有机层从分液漏斗下口流出7.W 、X 、Y 、Z 、M 五种短周期元素,原子序数依次增大.W 元素的原子最外层电子数是次外层的3倍;X 元素的原子核外s 能级上的电子总数与p 能级上的电子总数相等,且第一电离能都高于同周期相邻元素;Y 元素是地壳中含量最多的金属元素;Z 元素的单质可作半导体材料;M 基态原子核外有9种不同空间运动状态的电子,且只有一个不成对电子.下列说法正确的是( ) A .2MW -的键角比4MW -的键角大 B .第一电离能:W >Z >M >X >Y C .原子半径:W >X >Y >Z >M D .ZW 2的熔点比ZM 4的熔点高8.氮化硅(Si 3N 4)薄膜是一种性能优良的重要介质材料,常用于集成电路制造中的介质绝缘.一种以硅块(主要含Si ,杂质为少量Fe 、Cu 的单质及化合物)为原料制备氮化硅的工艺流程如下:已知:ⅰ.硅的熔点是1420℃,高温下氧气及水蒸气能明显腐蚀氮化硅; ⅱ.氮化炉中反应为2343Si(s)2N (g)Si N (s)Δ727.5kJ /mol H +=-.下列说法错误的是( )A .硅块粉碎能有效提高合成氮化硅的反应速率B .铜屑的作用是除去N 2中含有的少量O 2C .“酸洗”中稀酸X 可以选用氢氟酸D .合成过程中应严格控制N 2的流速以控制氮化炉中的温度9.某中学化学社进行沉淀溶解平衡相关实验,操作流程如下.下列说法正确的是( )已知:常温下,10sp (AgCl) 1.810K -=⨯,13sp (AgBr) 5.410K -=⨯,17sp (AgI)8.510K -=⨯ A .悬浊液a 中()Brc -与悬浊液d 中()Br c -相等B .步骤③可以证明sp sp (AgBr)(AgI)K K >C .向悬浊液e 中滴加几滴0.1mol/LNaCl 溶液,观察到黄色沉淀转化为白色沉淀D .向悬浊液d 中加入少量NaI 溶液,沉淀颜色不变时,()()4I 8.5105.4Br c c ---⨯=10.SOEC 装置是一种高温固体氧化物电解池,可以从大气中回收CO 2,其工作温度为600~1000℃,利用固态CeO 2中的2O-定向移动形成离子电流.SOEC 由多个层状工作单元叠加而成,拆解后装置如图所示(CO 2在电极b 上反应,外接电源与部分气体管路、流向未显示).下列说法正确的是( )A .电极b 为阳极,电极反应为22CO 2e CO O --++B .在气孔Z 附近检测到少量3Ce +,说明发生了电极反应:322CeO e Ce 2O -+-++C .装置工作过程中,CeO 2(s )电解质中的2O-由电极a 移向电极bD .由于产生有毒气体CO ,故必须将各层密封,防止气体泄露11.在刚性密闭容器中,放入一定量的NO (g )和足量C (s ),发生反应22C(s)2NO(g)CO (g)N (g)++,平衡状态时NO (g )的物质的量浓度与温度T 的关系如图所示.则下列说法正确的是( )A .在T 1时达到平衡,再向体系中充入NO ,达到新平衡时,NO 体积分数增大B .在T 2时,若反应体系处于状态D ,则此时一定有v (正)<v (逆)C .在T 3时,若混合气体的密度不再变化,则可以判断反应达到平衡状态D .若该反应在T 1、T 2时的平衡常数分别为K 1、K 2,则K 1<K 212.石墨是层状结构,许多分子和离子可以渗入石墨层间形成插层化合物.Li +插入石墨层中间,形成晶体结构如图(a ),晶体投影图如图(b ).若该结构中碳碳键键长为a pm ,碳层和锂层相距d pm (用N A 表示阿伏加德罗常数的值).下列说法错误的是( )A .石墨的二维结构中,每个碳原子配位数为3B .该插层化合物的化学式为LiC 6C .该插层化合物中同层Li +最近距离为3a pmD303A 10g cm -⋅ 13.常温下,用0.100mol/LNaOH 溶液分别滴定20.00mL0.100mol/L 的HX 和HY 的溶液,滴定曲线如图所示.下列说法正确的是( )A .a (HX)K 的数量级为710- B .水电离出的()H c +由大到小的顺序为C >B >AC .B 点满足()()()()YNa (HY)H OH c c c c c -++->>>>D .将HX 曲线上的A 点与C 点所得溶液混合,则存在()()X(HX)2Na c c c -++=14.我国科学家已经成功地利用二氧化碳催化氢化获得甲酸,利用化合物1催化氢化二氧化碳的反应过程如图甲所示,其中化合物2与水反应生成化合物3和HCOO -的反应历程如图乙所示,其中TS 表示过渡态,Ⅰ表示中间体.下列说法正确的是( )A .化合物2为此反应的催化剂B .从平衡移动的角度看,升高温度可促进化合物2与水反应生成化合物3与HCOO -C .图乙中形成中间体Ⅰ2的反应为图甲中22H O 3HCOO -+→+的决速步骤 D .化合物1到化合物2的过程中不存在极性键的断裂和形成二、非选择题(本题共4道题,共58分.)15.(15分)亚硝酸钠(NaNO 2)用途很广泛:可制药,作食品防腐剂、显色剂,作印染工业的媒染剂、漂白剂、缓蚀剂等.某兴趣小组欲制备亚硝酸钠并进行一定的实验探究,查阅资料可知:①222Na O 2NO2NaNO +;②2223Na O 2NO 2NaNO +;③NO 可被酸性KMnO 4氧化成3NO -. 【制备NaNO 2】用下图所示装置制备NaNO 2:(1)过氧化钠的电子式是_________. (2)仪器B 中Cu 的作用是_________. (3)U 形管C 中的试剂可以是_________. (4)试管E 中反应的离子方程式为_________.(5)以上装置有设计缺陷,会使产品NaNO 2中杂质增多.改进方法是__________________. 【测定NaNO 2纯度】(6)①称量0.5000g 制得的样品,溶于水配成500mL 溶液;②取25.00mL 待测液于锥形瓶中,加入足量KI 酸性溶液,滴入2~3滴淀粉溶液;③取一支_________(填“酸”或“碱”)式滴定管用蒸馏水洗净后,用0.01mol/LNa 2S 2O 3溶液润洗,装液,排出下端尖嘴内的气泡,调整液面,记下读数:④进行滴定,记录读数.重复实验后,平均消耗Na 2S 2O 3溶液的体积为20.00mL . (已知:22322162Na S O I 2NaI Na S O ++;2222NO 2I 4H 2NO I 2H O --+++↑++)(7)下列情况可能会使测得的NaNO 2纯度偏低的是_________(填标号). A .操作②中使用的锥形瓶未干燥 B .操作③中未排尽下端尖嘴内的气泡C .操作④当滴入半滴Na 2S 2O 3溶液,溶液由蓝色变为无色时,立即停止滴定D .整个滴定操作过慢,用时过长(8)样品中NaNO 2的质量分数为_________.16.(14分)金属镓被称为“电子工业脊梁”,今年8月1日,国家商务部开始对镓和锗两种金属进行出口管制,这一举措是对美国等国家对中国进行芯片技术封锁与5G 技术打压的有力回应,展示了我国的自信和决心.GaN 作为第三代半导体材料,具有耐高温、耐高电压等特性,随着5G 技术的发展,GaN 商用进入快车道.综合利用炼锌矿渣[主要含铁酸镓Ga 2(Fe 2O 4)3、铁酸锌ZnFe 2O 4]获得3种金属盐,并进一步利用镓盐制备具有优异光电性能的氮化镓(GaN ),部分工艺流程如下:已知:常温下,浸出液中各离子形成氢氧化物沉淀的pH 和金属离子在工艺条件下的萃取率(进入有机层中金属离子的百分数)见表:(1)GaN 属于_________晶体;Ga 2(Fe 2O 4)3中Fe 的化合价为_________. (2)处理浸出液时,将溶液的pH 调节至5.4的主要目的是__________________. (3)“溶解还原”步骤中需要加入一定量的铁粉,进行该操作的主要目的是_________.(4)Ga 的化学性质与Al 非常相似,“反萃取”后水溶液中镓元素主要以_________(用离子符号表示)形式存在.(5)“高温合成”操作中Ga (CH 3)3与NH 3反应生成GaN 的化学方程式为_________. (6)利用炼锌矿渣所获得的三种金属盐,分别为镓盐、FeCl 2和_________(用化学式表示).17.(14分)三烯(乙烯、丙烯、丁二烯)和三苯(苯、甲苯、二甲苯)是基本的化工原料,应用广泛.回答下列问题:(1)在三烯三苯中最重要的就是乙烯,乙烯产量甚至被作为衡量一个国家化工发展水平的指标.乙烷裂解法制取乙烯的反应机理如下: Ⅰ.链引发26331C H (g)CH CH ΔH →⋅+⋅Ⅱ.链传递3262542CH C H (g)C H CH (g)ΔH ⋅+→⋅+ 25243C H C H (g)H ΔH ⋅+⋅→ 262524H C H (g)C H H (g)ΔH ⋅+→⋅+Ⅲ.链终止(略)①乙烷裂解制乙烯的热化学方程式为_________.②反应机理中生成的3CH ⋅(甲基自由基)得电子变成3CH -(甲基负离子),3CH -的VSEPR 模型的名称为_________.(2)丙烯工业上常用“丙烯氨氧化法”制备丙烯腈(2CH CHCN ),包括如下反应: Ⅰ.()()()()()3632223C H g NH g O g CH CHCN g 3H O g 2+++Ⅱ.36222C H (g)O (g)CH CHCHO(g)H O(g)++(副反应)向T ℃、压强为28MPa 的恒压密闭容器中通入1.0mol 丙烯、1.0mol 氨气和4.8mol 氧气发生反应Ⅰ、Ⅱ,容器内H 2O (g )、2CH CHCN(g)=、C 3H 6(g )的物质的量(n )随时间(t )的变化关系如图所示. ①图中表示H 2O (g )的曲线是_________(填“a ”“b ”或“c ”). ②反应Ⅰ的浓度平衡常数K 的表达式为_________.③平衡时,2CH CHCN(g)=的分压()2CH CHCN p ==_________MPa .(3)国家发改委把生产尼龙-66的己二腈列为国家攻关的“卡脖子”项目,目前工业上生产己二腈主要为丙烯腈电解法.酸性条件下丙烯腈电解法制己二氰的阴极电极反应式为_________,其中丙烯氰中碳原子的杂化方式为_________.18.(15分)芳香化合物E 中含有两个六元环,合成路线如下:已知:3CH CH CHCHO =(羟醛缩合,酮类也有类似性质)回答下列问题:(1)反应①的试剂和条件是_________.反应②的反应类型是_________.(2)有机小分子B 的分子式是_________.(3)芳香化合物C 中含氧官能团的名称是_________. (4)反应③的化学方程式是_________.该反应过程中还可能生成另一种含有两个六元环的副产物,与E 互为同分异构体.该副产物的结构简式是_________.(5)有机化合物A 的芳香族同分异构体中,能发生加聚反应并能与FeCl 3发生显色反应的有_________种(不考虑立体异构).(6)设计以苯和乙酸为原料,制备的合成路线图.(无机试剂任选,合成中必须使用反应②的信息)英才大联考长郡中学2024届高三月考试卷(二)化学参考答案一、选择题(本题共14小题,每小题3分,共42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.)二、非选择题(本题共4道题,共58分.)15.(15分)(1) 2N O a a O N :::-++⎡⎤⎢⎥⎣⎦(2)与稀硝酸反应生成更多的NO (3)碱石灰(4)24323MnO 4H 5NO3Mn 5NO 2H O -++-++++(5)在装置D 、E 之间连接一个干燥装置(若指明装置中干燥剂,合理即可得分) (6)③碱 (7)C (8)55.2% 16.(14分) (1)共价 +3(2)使3Fe +、3Ca +完全转化为沉淀,2Zn+不沉淀(3)将铁离子转化为亚铁离子,避免铁离子被萃取 (4)2GaO -或()4Ga OH -⎡⎤⎣⎦(5)()3343Ga CH NH GaN 3CH ++高温(6)ZnSO 4 17.(14分) (1)①2624234C H (g)C H (g)H ΔΔ Δ H H H +=+ ②四面体形(2)①c ②()()()()()322323632CH CHCN H O C H NH O c c c c c =⨯⨯⨯ ③1.6(3)()2242CH CHCN 2H 2e NC CH CN +-++ 2sp 和sp18.(15分)(1)液溴、FeBr 3作催化剂 取代反应 (2)CH 2O (3)酮羰基(4)(5)16。

2024-2025学年湖南省长沙市长郡中学大联考高三(上)月考数学试卷(二)(含答案)

2024-2025学年湖南省长沙市长郡中学大联考高三(上)月考数学试卷(二)(含答案)

2024-2025学年湖南省长沙市长郡中学大联考高三(上)月考数学试卷(二)一、单选题:本题共8小题,每小题5分,共40分。

在每小题给出的选项中,只有一项是符合题目要求的。

1.已知集合A ={x||x|⩽2},B ={t|1⩽2t ⩽8(t ∈Z)},则A ∩B =( )A. [−1,3]B. {0,1}C. [0,2]D. {0,1,2}2.已知复数z 满足|z−i|=1,则|z|的取值范围是( )A. [0,1]B. [0,1)C. [0,2)D. [0,2]3.已知p :f(x)=ln(21−x +a)(−1<x <1)是奇函数,q :a =−1,则p 是q 成立的( )A. 充要条件 B. 充分不必要条件C. 必要不充分条件D. 既不充分也不必要条件4.若锐角α满足sinα−cosα=55,则sin (2α+π2)=( )A. 45B. −35 C. −35或35D. −45或455.某大学在校学生中,理科生多于文科生,女生多于男生,则下述关于该大学在校学生的结论中,一定成立的是( )A. 理科男生多于文科女生B. 文科女生多于文科男生C. 理科女生多于文科男生D. 理科女生多于理科男生6.如图,某车间生产一种圆台形零件,其下底面的直径为4cm ,上底面的直径为8cm ,高为4cm ,已知点P 是上底面圆周上不与直径AB 端点重合的一点,且AP =BP ,O 为上底面圆的圆心,则OP 与平面ABC 所成的角的正切值为( )A. 2B. 12C.5D.557.在平面直角坐标系xOy 中,已知直线l :y =kx +12与圆C :x 2+y 2=1交于A ,B 两点,则△AOB 的面积的最大值为( )A. 1B. 12C.32D.348.设函数f(x)=(x 2+ax +b)lnx ,若f(x)≥0,则a 的最小值为( )A. −2B. −1C. 2D. 1二、多选题:本题共3小题,共18分。

湖南省长沙市湖南师范大学附属中学2024届高三上学期月考卷(四)数学

湖南省长沙市湖南师范大学附属中学2024届高三上学期月考卷(四)数学

湖南师大附中2024届高三月考试卷(四)数学时量:120分钟 满分:150分一、选择题:本题共8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.已知复数12i z =+,其中i 为虚数单位,则复数2z 在复平面内对应的点的坐标为( )A.(4,5)- B.(4,3)C.(3,4)- D.(5,4))2.若随机事件A ,B 满足1()3P A =,1()2P B =,3()4P A B = ,则(|)P A B =( )A.29B.23C.14D.168.设{}n a 是公比不为1的无穷等比数列,则“{}n a 为递减数列”是“存在正整数0N ,当0n N >时,1n a <”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4.设0,2πα⎛⎫∈ ⎪⎝⎭,0,2πβ⎛⎫∈ ⎪⎝⎭,且1tan tan cos αβα+=,则( )A.22παβ+=B.22παβ-=C.22πβα-=D.22πβα+=5.若52345012345(12)(1)(1)(1)(1)(1)x a a x a x a x a x a x -=+-+-+-+-+-,则下列结论中正确的是( )A.01a = B.480a =C.50123453a a a a a a +++++= D.()()10024135134a a a a a a -++++=6.函数1()2cos[(2023)]|1|f x x x π=++-在区间[3,5]-上所有零点的和等于( )A.2B.4C.6D.87.点M 是椭圆22221x y a b+=(0a b >>)上的点,以M 为圆心的圆与x 轴相切于椭圆的焦点F ,圆M 与y 轴相交于P ,Q ,若PQM △是钝角三角形,则椭圆离心率的取值范围是()A.(0,2B.⎛ ⎝C.⎫⎪⎪⎭D.(2-8.已知函数22,0,()4|1|4,0,x x f x x x ⎧=⎨-++<⎩…若存在唯一的整数x ,使得()10f x x a -<-成立,则所有满足条件的整数a 的取值集合为( )A.{2,1,0,1}-- B.{2,1,0}-- C.{1,0,1}- D.{2,1}-二、选择题:本题共4小题,每小题5分,共20分.在每小题给出的选项中,有多项符合题目要求.全部选对的得5分,部分选对的得2分,有选错的得0分、9.已.知双曲线C过点且渐近线为y x =,则下列结论正确的是( )A.C 的方程为2213x y -= B.CC.曲线2e1x y -=-经过C 的一个焦点D.直线10x --=与C 有两个公共点10.已知向量a ,b满足|2|||a b a += ,20a b a ⋅+= 且||2a = ,则( )A.||8b = B.0a b += C.|2|6a b -=D.4a b ⋅= 11.如图、正方体1111ABCD A B C D -的棱长为2,点M 是其侧面11ADD A 上的一个动点(含边界),点P 是线段1CC 上的动点,则下列结论正确的是()A.存在点P ,M ,使得二面角M DC P --大小为23πB.存在点P ,M ,使得平面11B D M 与平面PBD 平行C.当P 为棱1CC的中点且PM =时,则点M 的轨迹长度为23πD.当M 为1A D 中点时,四棱锥M ABCD -12.若存在实常数k 和b ,使得函数()F x 和()G x 对其公共定义域上的任意实数x 都满足:()F x kx b +…和()G x kx b +…恒成立,则称此直线y kx b =+为()F x 和()G x 的“隔离直线”.已知函数2()f x x =(x ∈R ),1()g x x=(0x <),()2eln h x x =(e 2.718≈),则下列选项正确的是( )A.()()()m x f x g x =-在x ⎛⎫∈ ⎪⎝⎭时单调递增B.()f x 和()g x 之间存在“隔离直线”,且b 的最小值为–4C.()f x 和()g x 之间存在“隔离直线”,且k 的取值范围是[4,1]-D.()f x 和()h x之间存在唯一的“隔离直线”ey =-三、填空题:本题共4小题,每小题5分,共20分.13.已知函数()y f x =的图象在点(1,(1))M f 处的切线方程是122y x =+,则(1)(1)f f +'=___________.14.如图,由3个全等的钝角三角形与中间一个小等边三角形DEF 拼成的一个较大的等边三角形ABC ,若3AF =,sin ACF ∠=,则DEF △的面积为___________.15.已知数列{}n a 的首项132a =,且满足1323n n n a a a +=+.若123111181n a a a a ++++< ,则n 的最大值为___________.16.在棱长为3的正方体1111ABCD A B C D -中,点E 满足112A E EB =,点F 在平面1BC D 内,则|1||A F EF +的最小值为___________.四、解答题:本题共6小题,共70分.解答应写出文字说明、证明过程或演算步骤.17.(10分)已知函数2()2cos 2xf x x m ωω=++(0ω>)的最小值为–2.(1)求函数()f x 的最大值;(2)把函数()y f x =的图象向右平移6πω个单位长度,可得函数()y g x =的图象,且函数()y g x =在0,8π⎡⎤⎢⎥⎣⎦上单调递增,求ω的最大值.18.(12分)为了丰富在校学生的课余生活,某校举办了一次趣味运动会活动,学校设置项目A “毛毛虫旱地龙舟”和项目B “袋鼠接力跳”.甲、乙两班每班分成两组,每组参加一个项目,进行班级对抗赛.第一个比赛项目A 采取五局三胜制(即有一方先胜3局即获胜,比赛结束);第二个比赛项目B 采取领先3局者获胜。

湖南省长沙市长郡中学2024-2025学年高三上学期月考(一)物理试卷(含解析)

湖南省长沙市长郡中学2024-2025学年高三上学期月考(一)物理试卷(含解析)

大联考长郡中学2025届高三月考试卷(一)物理得分:________本试题卷分选择题和非选择题两部分,共8页。

时量75分钟。

满分100分。

第Ⅰ卷 选择题(共44分)一、选择题(本题共6小题,每小题4分,共24分。

每小题只有一项符合题目要求)1.下列关于行星和万有引力的说法正确的是A .开普勒发现了行星运动规律,提出行星以太阳为焦点沿椭圆轨道运行的规律,并提出了日心说B .法国物理学家卡文迪什利用放大法的思想测量了万有引力常量G ,帮助牛顿总结了万有引力定律C .由万有引力定律可知,当太阳的质量大于行星的质量时,太阳对行星的万有引力大于行星对太阳的万有引力D .牛顿提出的万有引力定律不只适用于天体间,万有引力是宇宙中具有质量的物体间普遍存在的相互作用力2.如图所示,甲,乙两柱体的截面分别为半径均为R 的圆和半圆,甲的右侧顶着一块竖直的挡板。

若甲和乙的质量相等,柱体的曲面和挡板可视为光滑,开始两圆柱体柱心连线沿竖直方向,将挡板缓慢地向右移动,直到圆柱体甲刚要落至地面为止,整个过程半圆柱乙始终保持静止,那么半圆柱乙与水平面间动摩擦因数的最小值为AB . CD .★3.我国首个火星探测器“天问一号”在海南文昌航天发射场由“长征5号”运载火箭发射升空,开启了我国行星探测之旅。

“天问一号”离开地球时,所受地球的万有引力与它距离地面高度的关系图像如图甲所示,“天问一号”奔向火星时,所受火星的万有引力与它距离火星表面高度的关系图像如图乙所示,已知地球半径是火星半径的两倍,下列说法正确的是A .地球与火星的表面重力加速度之比为3∶2B .地球与火星的质量之比为3∶2C .地球与火星的密度之比为9∶8121F 1h 2F 2hD4.如图所示,以O 为原点在竖直面内建立平面直角坐标系:第Ⅳ象限挡板形状满足方程(单位:m ),小球从第Ⅱ象限内一个固定光滑圆弧轨道某处静止释放,通过O 点后开始做平抛运动,击中挡板上的P 点时动能最小(P 点未画出),重力加速度大小取,不计一切阻力,下列说法正确的是A .P 点的坐标为B .小球释放处的纵坐标为C .小球击中P 点时的速度大小为5m/sD .小球从释放到击中挡板的整个过程机械能不守恒5.在如图所示电路中,电源电动势为E ,内阻不可忽略,和为定值电阻,R 为滑动变阻器,P 为滑动变阻器滑片,C 为水平放置的平行板电容器,M 点为电容器两板间一个固定点,电容器下极板接地(电势为零),下列说法正确的是A .左图中电容器上极板带负电B .左图中滑片P 向上移动一定距离,电路稳定后电阻上电压减小C .若将换成如右图的二极管,电容器上极板向上移动一定距离,电路稳定后电容器两极板间电压增大D .在右图中电容器上极板向上移动一定距离,电路稳定后M 点电势降低6.图甲为用手机和轻弹簧制作的一个振动装置。

湖南省(XXX)、江西省(XXX)等十四校2018届高三第二次联考数学(理)试题+Word版含答案

湖南省(XXX)、江西省(XXX)等十四校2018届高三第二次联考数学(理)试题+Word版含答案

湖南省(XXX)、江西省(XXX)等十四校2018届高三第二次联考数学(理)试题+Word版含答案2018届高三·十四校联考第二次数学(理科)考试第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,只有一项符合题目要求。

1.设集合A={x|x≥2},B={x|1<−x≤2},则A∩B=()A。

(-4,+∞) B。

[-4,+∞) C。

[-2,-1] D。

[-4,-2]2.复数z=xxxxxxxxxxxxxxxxi的共轭复数为()A。

3+i B。

-i C。

+i D。

-i3.下列有关命题的说法中错误的是()A。

设a,b∈R,则“a>b”是“aa>bb”的充要条件B。

若p∨q为真命题,则p,q中至少有一个为真命题C。

命题:“若y=f(x)是幂函数,则y=f(x)的图象不经过第四象限”的否命题是假命题D。

命题“∀n∈N,f(n)∈N且f(n)≤n”的否定形式是“∃n∈N*,f(n)∉N*且f(n)>n”4.已知不等式ax+1/x+2<0的解集为(-2,-1),则二项式(x+2)(ax-2)展开式的常数项是()A。

-15 B。

15 C。

-5 D。

55.若函数f(x)=3sin(π-ωx)+sin(5π+ωx/2),且f(α)=2,f(β)=3,α-β的最小值是π,则f(x)的单调递增区间是()A。

(2kπ-5π/3,2kπ-π/3) (k∈Z)B。

(2kπ-,2kπ+) (k∈Z)C。

(kπ-,5π/3+kπ) (k∈Z)D。

(kπ-π/3,5π/3+kπ) (k∈Z)6.某几何体的三视图如图所示(单位:cm),则该几何体的表面积(单位:cm)是()A。

40+125 B。

40+245 C。

36+125 D。

36+2457.甲、乙、丙、丁、戊五位同学相约去学校图书室借A、B、C、D四类课外书(每类课外书均有若干本),已知每人均只借阅一本,每类课外书均有人借阅,且甲只借阅A类课外书,则不同的借阅方案种类为()A。

湖南省长沙长郡中学2015届高三上学期第四次月考生物试题(word版)

湖南省长沙长郡中学2015届高三上学期第四次月考生物试题(word版)

湖南省长沙长郡中学2015届高三上学期第四次月考生物试题(word版)时量:90分钟满分:90分本试题卷分选择题和非选择题两部分。

时量90分钟,满分90分。

第I卷选择题(共40分)一、选择题(每小题给出的四个选项中,只有一个符合题目要求的。

将选出的正确答案填在答题卡上。

1~30每小题1分,31~35每题2分,共40分)1.埃博拉病毒是迄今发现的致死率最高的病毒之一,尚无有效治疗方法。

埃博拉病毒的潜伏期从2天到21天不等,目前感染埃博拉病毒的已知主要渠道是直接接触感染者的血液、分泌物及其他体液,或接触感染者的尸体。

下列有关病毒的叙述正确的是①病毒无细胞结构,一般由蛋白质和核酸构成②所有动植物的致病因子一定是病毒③埃博拉病毒可在实验室中用液体培养基培养④病毒在生物圈中的分布十分广泛⑤病毒是生命系统的最基本结构层次⑥病毒的遗传物质是DNA或RNAA.①③⑥I).②③⑤C.①④⑥D.③④⑤2.生物膜对于维持细胞正常的结构、功能具有非常重要的作用,下列相关叙述不正确的是A.细胞膜的组成元素与核酸相似B.线粒体、叶绿体、高尔基体等都是具膜结构的细胞器C.细胞的融合、细胞的变形运动以及胞吞、胞吐等与细胞膜的结构特性密切相关D.如果用单层磷脂分子构成的脂球体包裹某种药物,则该药物应该属于水溶性的3.有两瓶酵母菌培养液,A瓶中含有32 P,I3瓶中含有弱S,将两份酵母菌分别置于A、B 两瓶中培养一段时间,则在A、B瓶中都会带上放射性的细胞结构包括①染色体②线粒体③内质网④高尔基体⑤核糖体⑥细胞膜A.②③④⑥B.①②⑤C.②③④⑤⑥D.①②③④⑤⑥4.右图为电镜下观察的某细胞的一部分。

下列有关该细胞的叙述中,正确的是A.此细胞既可能是真核细胞也可能是原核细胞I).此细胞既可能是动物细胞也可能是植物细胞C.结构1、2、4、5、6均是由生物膜构成D.胸腺嘧啶参与碱基互补配对的有1和35.有一条多肽链,分子式为CxHyOpNqS,将它彻底水解后,只得到下列四种氨基酸:分析推算可知,水解得到的氨基酸个数为A.p-l B.q+-1 C.q—1 D.p+16.下图是油菜种子在发育和萌发过程中,糖类和脂肪的变化曲线。

推荐-人大附中2018届高三数学月考试卷2018及答案精品

推荐-人大附中2018届高三数学月考试卷2018及答案精品

人大附中2018届高三数学月考试卷18.10本试卷分第I 卷(选择题)和第II 卷(非选择题)两部分. 第I 卷1至2页.第II 卷3至9页.共150分. 考试时间120分钟.第I 卷(选择题共40分)一、选择题:本大题共8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.已知函数)0(3)0(log )(2x x x x f x ,则1[()]4f f 的值为()(A )9(B )91(C )-9 (D )912.条件:12p x ,条件:2q x,则p 是q 的()(A )充分非必要条件(B )必要不充分条件(C )充要条件(D )既不充分也不必要的条件3.已知538f xx ax bx ,且f (-2)=10,那么f (2)等于().(A )10(B )-10 (C )-18 (D )-26 4.已知函数2111f xx x ,则113f 的值是()(A )-2(B )-3 (C )1 (D )3 5.若2log 3a ,3log 2b,13log 2c ,21log 3d ,则,,,abcd 的大小关系是()(A )a bc d (B )d b c a (C )d c b a(D )c d a b 6.函数log 11a y xa 的大致图像是()(A )(B )(C )(D )7.设f x 是定义在R 上的奇函数,且在0,上单调递增,又30f ,则O x y O x y -1 O 1 xy-1 O 1 x yxf x的解集为()(A)(3,)3,0(B)(3,),3(C)(3,0)(0,3)(D)(0,3),38.(理科做)若函数y f x的图像可由函数lgy x的图像绕原点逆时针旋转而得到,则f x=()2(A)10x(B)10x(C)10x(D)10x(文科做)函数y=x2-2x+3 (x≤0)的反函数是( )(21xyxxy(B))2(2(A))31x1xxy(21x(C))3(2xy(D))2人大附中2018届高三数学月考试卷第Ⅱ卷(非选择题共110分)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.(理科做)复数312ii 的虚部为____________.(文科做)函数)0(1212x y x x 的反函数的定义域为____________.10.已知函数f x 是偶函数,并且对于定义域内任意的x ,满足12f x f x ,若当23x 时,f x x ,则f x 是以_________为最小正周期的周期函数,且2003.5f ________________.11.某工厂6年来生产某种产品的总产量C (即前t 年年产量之和)与时间t (年)的函数关系如图所示,则关于下面的几种说法中,正确的是_________________(1)前三年中,年产量增长的速度越来越快;(2)前三年中,年产量增长的速度越来越慢;(3)后三年中,这种产品的年产量保持不变;(4)第三年后,这种产品停止生产.12.若函数2f x a x b 在[0,)上为增函数,则实数a 的取值范围为_______________,b 的取值范围为_________________.13.将y =3log x 的图象作其关于直线y =x 的对称图象后得到图象C 1,再作C 1关于y 轴对称的图象后得到图象C 2,再将C 2的图象向右平移1个单位得到图象C 3,最后再作C 3关于原点对称的图象得到C 4,则C 4所对应的函数的解析表达式是.14.(理科做)一袋中装有1个白球和四个黑球,每次从其中任取一个球,取出球后便不再放回,若用表示第一次取到白球时取球的次数,则E =_______________,D =______________.O 3 6 t C(文科做)一袋中装有2个白球和四个黑球,每次从其中任取一个球,取出球后便不再放回,若用k 表示第一次取到白球时取球的次数,则1k 的概率为_______________;2k 的概率为_______________.三、解答题:本大题共6小题.共80分.15.(本小题14分)已知f (x)=xx a 11log (a>0, a ≠1),(1)求f (x)的定义域;(2)判断f (x)的奇偶性并给予证明;(3)求使f (x)>0的x 的取值范围.16.(本小题12分)定义在2,2上的偶函数g x 满足:当0x 时,g x 单调递减.若1g m g m ,求m 的取值范围.17.(本小题14分)定义在[-1,1]上的奇函数f x 满足11f,且当,1,1a b ,0a b 时,有0f a f ba b .(1)求证:f x 是[-1,1]上的增函数.(2)证明:当113x 时,3f x x .(3)若221f x m am 对所有1,1x ,1,1a 恒成立,求m 的取值范围.18.(本小题14分)(理科做)设二次函数2,f xx bx c b c R ,对于任意,恒有sin 0f ,2cos 0f .(1)求证:1b c且3c .(2)若函数sin f 的最大值为8,求,b c 的值.(文科做)已知函数22()4422()f x x mx m m m R 在区间[0,2]上的最小值是5,求m 的值.19.(本小题13分)用水清洗一堆蔬菜上残留的农药,对用一定量的水清洗一次的效果作如下假定:用一个单位量的水可洗掉蔬菜上残留农药量的32,用水越多洗掉的农药量也越多,但总还有农药量残留在蔬菜上.设用x 单位的水清洗一次以后,蔬菜上残留的农药量与本次清洗前残留的农药量之比为函数f x .(1)试规定0f 的值,并说明其实际意义.(2)试根据假定写出函数f x 应满足的条件和具有的性质.(3)设2112f x x ,现有0a a单位量的水,可以清洗一次,也可以把水平均分成两份后清洗两次,试问哪种方案清洗后蔬菜上残留的农药量比较少?说明理由.20.(本小题13分)(理科做)已知22cos sin f xx x .(1)若f x 的定义域为R , 求值域;(2)f x 在区间]2,0[上是不是单调函数?证明你的结论;(3)设y f x ,若对于y 在集合M 中的每一个值,x 在区间),0(上恰有两个不同的值与之对应,求集合M . (文科做)记函数f x 的定义域为D ,若存在0x D 使得00f x x 成立,则称以00,x x 为坐标的点是函数图像上的“稳定点”.(1)若函数31x f xx a 的图像上有且仅有两个相异的稳定点,试求实数a的取值范围;(2)已知定义在实数集上的奇函数f x 存在有限个稳定点,求证:f x 必有奇数个稳定点.。

湖南省长沙市2018年中考数学试题(word版,含答案)

湖南省长沙市2018年中考数学试题(word版,含答案)

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湖南省长沙市长郡中学2023-2024学年高三下学期适应考试(二)数学试题含答案

湖南省长沙市长郡中学2023-2024学年高三下学期适应考试(二)数学试题含答案

长郡中学2024届高考适应性考试(二)数学命题人:__________审题人__________注意事项:1.答卷前,考生务必将自己的姓名、准考证号填写在答题卡上.2.回答选择题时,选出每小题答案后,用铅笔把答题卡上对应题目的答案标号涂黑.如需改动,用橡皮擦干净后,再选涂其他答案标号.回答非选择题时,将答案写在答题卡上.写在本试卷上无效.3.考试结束后,将本试卷和答题卡一并交回.一、选择题:本题共8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.已知集合{}{}2230,2,1xA xx x B y y x =--<==<∣∣,则A B ⋂=()A.(),3∞-B.()0,2C.()1,2-D.()2,32.已知数列{}n a 满足111n n a a +=-,若112a =,则2023a =()A.2B.-2C.-1D.123.已知样本数据12100,,,x x x 的平均数和标准差均为4,则数据121001,1,,1x x x ------ 的平均数与方差分别为()A.5,4- B.5,16- C.4,16D.4,44.蒙古包(Mongolianyurts )是蒙古族牧民居住的一种房子,建造和搬迁都很方便,适于牧业生产和游牧生活,蒙古包古代称作穹庐、毡包或毡帐.已知蒙古包的造型可近似的看作一个圆柱和圆锥的组合体,已知圆锥的高为2米,圆柱的高为3米,底面圆的面积为64π平方米,则该蒙古包(含底面)的表面积为()A.(112π+平方米B.(80π+平方米C.(112π+平方米D.(80π+平方米5.儿童玩具纸风车(图1)体现了数学的对称美.取一张正方形纸折出“十”字折痕,然后把四个角向中心点翻折,再展开,把正方形纸两条对边分别向中线对折,把长方形短的一边沿折痕向外侧翻折,然后把立起来的部分向下翻折压平,另一端折法相同,把右上角的角向上翻折,左下角的角向下翻折,纸风车的主体部分就完成了(图2).则()A.OC OE=B.0OA OB ⋅>C.2OA OD OE+=D.0OA OC OD ++=6.已知函数()()πtan 0,02f x x ωϕωϕ⎛⎫=+><< ⎪⎝⎭的最小正周期为2π,直线π3x =是()f x 图象的一条对称轴,则()f x 的单调递减区间为()A.()π5π2π,2π66k k k ⎛⎤-+∈ ⎥⎝⎦Z B.()5π2π2π,2π33k k k ⎛⎤--∈ ⎥⎝⎦Z C.()4ππ2π,2π33k k k ⎛⎤--∈ ⎥⎝⎦Z D.()π2π2π,2π33k k k ⎛⎤-+∈ ⎥⎝⎦Z 7.已知1sin cos ,0π5ααα-=≤≤,则πsin 24α⎛⎫-= ⎪⎝⎭()A.50-B.50 C.50-D.508.已知复数12,z z 满足112881i 1i z z z p p p p ⎛⎫+-+-+==+++ ⎪⎝⎭,(其中0,i p >是虚数单位),则12z z -的最小值为()A.2B.6C.2- D.2+二、多选题:本题共3小题,每小题6分,共18分.在每小题给出的选项中,有多项符合题目要求.全部选对的得6分,部分选对的得部分分,有选错的得0分.9.下列函数中最小值为2的是()A.223y x x =++ B.1sin sin y x x=+C.122x xy -=+ D.1ln ln y x x=+10.若,x y 满足28()23x y xy +-=,则()A.y x -≥B.2y x -<C.32xy >D.34xy ≥-11.在正方体1111ABCD A B C D -中,1,AB E =为11A D 的中点,F 是正方形11BB C C 内部一点(不含边界),则()A.平面1FBD ⊥平面11AC DB.平面11BB C C 内存在一条直线与直线EF 成30 角C.若F 到BC 边距离为d ,且221EF d -=,则点F 的轨迹为抛物线的一部分D.以11AA D 的边1AD 所在直线为旋转轴将11AA D 旋转一周,则在旋转过程中,1A 到平面1AB C 的距离的取值范围是3636,3535-+⎣⎦三、填空题:本题共3小题,每小题5分,共15分.12.已知6m x x ⎛⎫+ ⎪⎝⎭的展开式中常数项为20,则实数m 的值为__________.13.已知定义在R 上的偶函数()f x 满足()()()1212f x f x f x x =,且当0x >时,()0f x >.若()()33f f a =',则()f x 在点11,33f ⎛⎫⎛⎫-- ⎪ ⎪⎝⎭⎝⎭处的切线方程为__________.(用含a 的表达式表示)14.已知双曲线22:13y C x -=的左、右焦点分别为12,F F ,右顶点为E ,过2F 的直线交双曲线C 的右支于,A B 两点(其中点A 在第一象限内),设,M N 分别为1212,AF F BF F 的内心,则当1F A AB ⊥时,1AF =__________;1ABF 内切圆的半径为__________.四、解答题:本题共5小题,共77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)已知在ABC 中,内角,,A B C 所对的边分别为,,a b c ,其中4,sin a C c A ==-.(1)求A ;(2)已知直线AM 为BAC ∠的平分线,且与BC 交于点M ,若223AM =,求ABC 的周长.16.(本小题满分15分)如图,已知ABCD 为等腰梯形,点E 为以BC 为直径的半圆弧上一点,平面ABCD ⊥平面,BCE M 为CE 的中点,2,4BE AB AD DC BC =====.(1)求证:DM ∥平面ABE ;(2)求平面ABE 与平面DCE 所成角的余弦值.17.(本小题满分15分)据统计,2024年元旦假期,哈尔滨市累计接待游客304.79万人次,实现旅游总收入59.14亿元,游客接待量与旅游总收入达到历史峰值.现对某一时间段冰雪大世界的部分游客做问卷调查,其中75%的游客计划只游览冰雪大世界,另外25%的游客计划既游览冰雪大世界又参观群力音乐公园大雪人.每位游客若只游览冰雪大世界,则得到1份文旅纪念品;若既游览冰雪大世界又参观群力音乐公园大雪人,则获得2份文旅纪念品.假设每位来冰雪大世界景区游览的游客与是否参观群力音乐公园大雪人是相互独立的,用频率估计概率.(1)从冰雪大世界的游客中随机抽取3人,记这3人获得文旅纪念品的总个数为X ,求X 的分布列及数学期望;(2)记n 个游客得到文旅纪念品的总个数恰为1n +个的概率为n a ,求{}n a 的前n 项和;n S (3)从冰雪大世界的游客中随机抽取100人,这些游客得到纪念品的总个数恰为n 个的概率为n b ,当n b 取最大值时,求n 的值.18.(本小题满分17分)在椭圆(双曲线)中,任意两条互相垂直的切线的交点都在同一个圆上,该圆的圆心是椭圆(双曲线)的中心,半径等于椭圆(双曲线)长半轴(实半轴)与短半轴(虚半轴)平方和(差)的算术平方根,则这个圆叫蒙日圆.已知椭圆2222:1(0)x y E a b a b+=>>的蒙日圆的面积为13π,该椭圆的上顶点和下顶点分别为12P P 、,且122PP =,设过点10,2Q ⎛⎫⎪⎝⎭的直线1l 与椭圆E 交于,A B 两点(不与12,PP 两点重合)且直线2:260l x y +-=.(1)证明:12,AP BP 的交点P 在直线2y =上;(2)求直线122,,AP BP l 围成的三角形面积的最小值.19.(本小题满分17分)帕德近似是法国数学家亨利·帕德发明的用有理多项式近似特定函数的方法.给定两个正整数,m n ,函数()f x 在0x =处的[],m n 阶帕德近似定义为:()0111m m nn a a x a x R x b x b x +++=+++ ,且满足:()()()()()()()()()()00,00,00,,00m n m n f R f R f R f R ++''''='='== .(注:()()()()()()()()()()()()()''''454,,,,;n f x f x f x f x f x f x f x f x f x '''''⎦'''''⎡⎤====⋯⎡⎤⎡⎤⎡⎤⎣⎦⎣⎣⎦⎦'⎣为()()1n f x -的导数)已知()()ln 1f x x =+在0x =处的[]1,1阶帕德近似为()1axR x bx=+.(1)求实数,a b 的值;(2)比较()f x 与()R x 的大小;(3)若()()()()12f x h x m f x R x ⎛⎫=-- ⎪⎝⎭在()0,∞+上存在极值,求m 的取值范围.长郡中学2024届高考适应性考试(二)数学参考答案一、选择题:本题共8小题,每小题5分,共40分。

湖南省衡阳县2018届高三12月联考数学(理)试题Word版含解析

湖南省衡阳县2018届高三12月联考数学(理)试题Word版含解析

数学试卷(理)第I卷(共60分)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.设集合A = {x|4x-x2 < 0},B = {y|y > 0} > 则AClB=()A. 0B. (0, 4)C. (4, + oo)D. (0, + oo)【答案】C【解析】由题意可得:A = {xlx > 4或v 0厂结合交集的定义可知A n B = (4, +8),本题选择c选项.2.将函数f(x) = SIHTCX的图象向右平移!个单位长度后得至血(x)的图象,则()1A. g(x) = sin(兀x--)B. g(x) = cos7ux1C. g(x) = sin(兀x + -)D. g(x) = -cos7cx【答案】D【解析】由函数图像的平移性质可知,平移后函数的解析式为:x-扌)=sin n(x-扌)=sin( nx-^j = -cosnx-g(x)= f(本题选择D选项.3.在等比数列中,a i a2a5 = a4,贝〔J ()A. |a2| = lB. 3^2= 1 C・ |a3| = 1 D. a2a3 = 1【答案】A【解析】由等比数列的通项公式有:引(34)(3®) =引qX整理可得:(a iq)2 = 1,即|a2| = l.本题选择A选项.点睛:熟练掌握等比数列的一些性质可提高解题速度,历年高考对等比数列的性质考查较多, 主耍是考查“等积性”,题目“小而巧”且背景不断更新.解题时耍善于类比并且要能•正确区分等差、等比数列的性质,不要把两者的性质搞混.4.已矢口向量a = (l,x),b = (x,y-2),其中x>0,若a与b共线,贝忆的最小值为( )xA. QB. 2C. 2&D. 4【答案】C【解析]V a = (l,x)> b = (x,y-2)>其中x>0,且;与&共线1 X (y-2) = X • X,即y =x2 + 2・・・4 = = x + ?N2Q,当且仅当x = -BPx = ^时取等号XX X X・・.Y的最小值为2血X故选C点睛:在应用基本不等式求最值时,要把握不等式成立的三个条件,就是“一正一一各项均为正;二定一一积或和为定值;三相等一一等号能否取得”,若忽略了某个条件,就会11!现错误.5.若函数f(x) = 2x_a + 1 + ^-a的定义域与值域相同,贝山=()A. -1B. 1C. 0D. ±1【答案】B【解析】T 函数f(x) = 2x_a +1 + Jx-a-a・・・函数f(x)的定义域为[a,+ s)•・•函数f(x)的定义域与值域相同函数f(x)的值域为[a, 4- oo)・・・函数f(x)在[a, + oo)上是单调减函数当x = a时,f(a) = 2a~a+1-a = a,即a = 1故选Bsinx 兀兀6.函数f(x)= ------------- 在[-芯]上的图象为( )x2+|x|+l 22【答案】B【解析】函数的解析式满足f(-x) = -f(x),则函数为奇函数,排除CD选项,] 3由|sinx|< l,x2 + |x| + 1 = (|x|+ + 4~ 1可知:IKx)|Sl,排除A 选项.本题选择B选项.sina-cosa 1 _ t7.右一------ =-tana,贝!jtan(x= ( )sina + cosa 6A. 一或一B. 一一或■一C. 2 或3D. -2 或-32 3 2 3【答案】CtsnOr~ 1【解析】由题意结合同角三角函数基本关系可得: --------- t ana,tana + 1 6整理可得:tan'a-5tana +6 = 0’求解关于tana的方程可得:tana=2或tana = 3.木题选择0选项.8.已知a,b,cW(0,2),4—y = logia,2b = logib,4—J = 贝g()2 2A・ a>b>c B. a>c>b C・ c>a>b D. c>b>a【答案】A【解析】如图所示,绘制函数y = 4-x2,y = 2"和厂的图像,三个方程的根为图中点A,B,C,■的横坐标,观察可得:x c>x B>x A,即Wc>b>a.本题选择D选项.9.某科技股份有限公司为激励创新,计划逐年增加研发资金投入,若该公司2016年全年投入的研发资金为100万无,在此基础上,每年投入的研发资金比上一年增长10%,则该公司全年投入的研发奖金开始超过200万元年年份是( )(参考数据:1卽.1= 0.041,览2 = 0.301) 2022 年 B. 2023 年 C. 2024 年 D. 2025 年【答案】0【解析】设从2016年后,第n年该公司全年投入的研发资金开始超过200万元,由题意可得:100x(1 +10%)、200,即l.l n>2,两边取对数可得:n> 仝 =^匕7.3,lgl.l 0.041则门> 8,即该公司全年投入的研发奖金开始超过200万元年年份是2024年.本题选择C选项./X+2,-2<x< 1,10.如图,函数f(x)= } <x<4的图象与X轴转成一个山峰形状的图形,设该图形夹在两条直线x = t,x = t+2(-2<t<2)Z间的部分的面积为S(t),则下列判断正确的是()A. S(0) = 41n2 + 2B. S(-2) = 2S(2)C. S(t)的极大值为S ⑴D. S(t)在[-2, 2]上的最大值与最小值之差为6-41n2【答案】D4S(-2) = 2, S(2) = I(--l)dx = (41nx-x)= 41n2-2,所以S(-2)^2S(2),故B 错误;对于C, S(t)的极J X 2大值为S(-l),故C 错误;对于D, S(t)在[-2,2]上的最大值与最小值分别为S(-1) = 4, S(2) = 41n2-2, 故D 正确. 故选D丄A+ 2'11.在数列{%}中,(口-1)2“ + % + ] = (n+l)an + 4n(n+1),且引=1,记T n = V 一:—,则() i= 21A. Tw 能被41整除B. T ]9能被43整除C. Tw 能被51整除【答案】A【解析】由数列的递推公式可得:n+1 nna I1+1 + n2n+1-(n + l)a n -(n + l)2nn(n+ 1)n a n + i-(ri + 1風]一(门+ 1)2" n(n+ 1)nan + rCn + l)a n 4- (n-l)2nn(n + 1)结合(n-l)2n + na n + 】=(n + l)a n + 4n(n + 1)可得:+?n+1 a 一 2“ 知+ 1十/ a n / =4> n+ 1 n + 2】是首项为二二=3,公差为4的等差数列,1据此可得:T ]9能被41整除 本题选择A 选项.2 +3 【解析】对于A, S(0) = 〒 f 45 :+ 1(一-l)dx = 一 +(41nx_x)] J 173> =毗+戸弘2 + 2,故A 错误;对于D. T ]9能被57整除则数列 则口:卄,故计丈亡n乞1(7 + 75)X18= 41X 18,2点睛:数列的递推关系是给岀数列的一种方法,根据给岀的初始值和递推关系对以依次写岀这个数列的各项,由递推关系求数列的通项公式,常用的方法有:①求出数列的前几项,再归纳猜想出数列的一个通项公式;②将已知递推关系式整理、变形,变成等差、等比数列,或用累加法、累乘法、迭代法求通项.12.已知函数f(x) = (疋*2;6%*»0 ,若恰好存在3个整数x,使得些芒成立,则满足条(-X-3X24-4,X<0 x件的整数3的个数为( )A. 34B. 33C. 32D. 25【答案】A【解析】画Hlf(x)的函数图象如图所示:当x>0 时,f(x) > a,当xvO 时,a > f(x) •••f(3) = _3 x9+18 = _9, f(4)=_3xl6 + 24 = _24, f(_l) = _(_1产3 x (_1『+ 4 = 2,f(~3) = 一(一3)'-3 x(一3)2 + 4 = 4,f(—4) = —(—4)^~3 x (~4)2 + 4 = 20•••当a<0时,-24<a<-9;当0SaS3时,a = 0, 2<a<3;当a>3时,4<a<20・・•恰好存在3个整数x,使得愆芒二0成立X・••整数a的值为-23, -22, • • • . -9及0, 2, 3, 4. 5.….19,共34 个故选A 点睛:对于方程解的个数(或函数'零点个数)问题,可利用函数的值域或最值,结合函数的单调性、草图确定其中参数范围.从图象的最高点、最低点,分析函数的最值、极值;从图象的对称性,分析函数的奇偶性;从图彖的走向趋势,分析函数的单调性、周期性等第II卷(共90分)二、填空题(每题5分,满分20分,将答案填在答题纸上)13._________________________________________________________________ 己知函数f(x)的周期为4,当xE[l,4)时,f(x) = 21og3x,则f(15) = __________________________________ .【答案】2【解析】・・•函数f(x)的周期为4.\f(15) = f(4x3 + 3) = f(3)•・•当xE [1,4)时,f(x) = 21og 3x.-.f(15) = f(3) = 21og 33 = 2故答案为214. ___________________________________________________________________________ 在边长为6的正AABC 中,D 为AC 边上的一点,且CD = 2DA,则BD • CB = ____________________【答案】-24【解析】•・• BD = BA + ^i), D 为AC 边上的一点,且CD = 2DAT 1 -> ・•・ AD = -AC3.\ro-CT = (^ + AD) -CT = ^-CB +AD* CB=BA- CB + -AC- CB *.• A ABC 是边长为6的正三角形 ABA • CB = |BA| - |CB| - cos 120° = 6 x 6 x AC • CB = |AC| • |CB|cosl20° = 6x6 .•.BD -CB = -18 + ^X (-18) = -24故答案为-24115. 若曲线y = xln(x-n)(n EN* )在乂轴的交点处的切线经过点(1,知),则数列{—}的前n 项和a nSn = ___________ •【答案】n+ 1【解析】令xln(x-n) = 0,得x = n + 1,则切点为(n + 1,0)■ X Vy = ln(x-n) + ——x-n •;yix 十I=n+1•:曲线y =xln(x-n)在x 轴的交点处的切线方程为y = (n+ l)(x-nT) •••切线经过点(1州)a n = -n(n + 1)知 n(n + 1) n n+ 11 1 1 1 1 nA S n = -(l — + ------ + • •・ + ------------ )= ---------n223 n n+1 n+11 = -18,n+ 1故答案为点睛:应用导数求曲线切线的斜率时,要注意“在某点的切线”与“过某点的切线”的区别, 否则容易出错。

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2018届湖南省长沙市长郡中学高三第四次月考数学(理)试题(解析
版)
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.
【答案】B
【解析】,,故选B.
2. 若复数满足(为虚数单位),则复数在复平面内对应的点位于()
A. 第一象限
B. 第二象限
C. 第三象限
D. 第四象限
【答案】C
【解析】因为,所以该复数在复平面内对于的点位于第三象限,应选答案C。

3. 已知向量,则“”是“与夹角为锐角”的()
A. 充分不必要条件
B. 充要条件
C. 必要不充分条件
D. 既不充分也不必要条件
【答案】C
【解析】若与夹角为锐角,则,且与不平行,所以,得,且,

所以“”是“,且”的必要不充分条件。

故选C。

4. 在展开式中,二项式系数的最大值为,含项的系数为,则()
A. B. C. D.
【答案】B
【解析】由题设可得,则,应选答案B。

5. 一名法官在审理一起珍宝盗窃案时,四名嫌疑人甲、乙、丙、丁的供词如下,甲说:“罪犯在乙、丙、丁三人之中”;乙说:“我没有作案,是丙偷的”;丙说:“甲、乙两人中有一人是小偷”;丁说:“乙说的是事实”.经过调查核实,四人中有两人说的是真话,另外两人说的是假话,且这四人中只有一人是罪犯,由此可判断罪犯是()
A. 甲
B. 乙
C. 丙
D. 丁
【答案】B
【解析】∵乙、丁两人的观点一致,∴乙、丁两人的供词应该是同真或同假;
若乙、丁两人说的是真话,则甲、丙两人说的是假话,由乙说真话推出丙是罪犯的结论;由甲说假话,推出乙、丙、丁三人不是罪犯的结论,矛盾;∴乙、丁两人说的是假话,而甲、丙两人说的是真话;由甲、丙的供述内容可以断定乙是罪犯.
6. 一个三棱锥的三视图如下图所示,则该几何体的体积为()
A. 1
B.
C. 2
D.
【答案】C
【解析】由三视图可得到如图所示几何体,该几何体是由正方体切割得到的,利用传统法或空间向量法可求得三棱锥的高为,∴该几何体的体积为.
点睛:三视图问题的常见类型及解题策略
(1)由几何体的直观图求三视图.注意正视图、侧视图和俯视图的观察方向,注意看到的部分用实线表示,不能看到的部分用虚线表示.
(2)由几何体的部分视图画出剩余的部分视图.先根据已知的一部分三视图,还原、推测直观图的可能形式,然后再找其剩下部分三视图的可能形式.当然作为选择题,也可将选项逐项代入,再看看给出的部分三视图是否符合.
(3)由几何体的三视图还原几何体的形状.要熟悉柱、锥、台、球的三视图,明确三视图的形成原理,结合空间想象将三视图还原为实物图.
7. 已知是平面内夹角为的两个单位向量,若向量满足,则的最大值为()
A. 1
B.
C.
D. 2
【答案】B
【解析】试题分析:由已知,
,(是与的夹角),∴,而,因此的最大值为.
考点:向量的数量积,向量的模.
8. 执行如图所示的程序框图,则输出的值为()
A. 1009
B. -1009
C. -1007
D. 1008
【答案】B
【解析】由程序框图则,由规律知输出
.故本题答案选.
【易错点睛】本题主要考查程序框图中的循环结构.循环结构中都有一个累计变量和计数变量,累计变量用于输出结果,计算变量用于记录循环次数,累计变量用于输出结果,计数变量和累计变量一般是同步执行的,累加一次计数一次,哪一步终止循环或不能准确地识别表示累计的变量,都会出现错误.计算程序框图的有关的问题要注意判断框中的条件,同时要注意循环结构中的处理框的位置的先后顺序,顺序不一样,输出的结果一般不会相同.
9. 已知斜率为3的直线与双曲线交于两点,若点是的中点,则双曲线的离心率等于()
A. B. C. 2 D.
【答案】A
【解析】设,
则,
所以,,
所以,得,所以,
所以。

故选A。

10. 若一个四位数的各位数字相加和为10,则称该数为“完美四位数”,如数字“2017”.试问用数字
0,1,2,3,4,5,6,7组成的无重复数字且大于2017的“完美四位数”有()个.
A. 53
B. 59
C. 66
D. 71
【答案】D
【解析】由题设中提供的信息可知:和为10四位数字分别是(0,1,2,7),(0,1,3,6),(0,1,4,5)(0,2,3,5),(1,2,3,4)共五组;其中第一组(0,1,2,7)中,7排首位有种情形,2排首位,1、7排在第二位上时,有种情形,2排首位,0排第二位,7排第三位有1种情形,共种情形符合题设;第二、三组中3,、6与4、5分别排首位各有种情形,共有种情形符合题设;第四、五组中2、3、5与2、3、4分别排首位各有种情形,共有种情形符合题设。

依据分类计数原理可符合题设条件的完美四位数共有种,应选答案D。

点睛:分类计数原理与分步计数原理是排列组合中的重要数学思想和方法。

求解本题时,充分借助题设中的完美四位数的定义,巧妙运用分类计数原理与分步计数原理进行分析求解,从而使得问题巧妙获解。

11. 椭圆的左焦点为,上顶点为,右顶点为,若的外接圆圆心在直线
的左下方,则该椭圆离心率的取值范围为()
A. B. C. D.
【答案】A
【解析】设,且的外接圆的方程为,将
分别代入可得,由可得,即
,所以,即,所以,应选答案A。

点睛:解答本题的思路是先借助圆的一般式方程,进而求出三角形外接圆的圆心坐标为,然后依据题设建立不等式,即,然后借助参数之间的关系求出椭圆离心率的取值范围使得问题获解。

12. 已知函数,若有两个零点,则的取值范围是()
A. B. C. D.
【答案】D
【解析】如图,
所以,令,则,
又有两个零点,
则有解,则存在解,
又,
所以令,且,,
所以,
令,则,
所以在单调递增,则,
所以的范围是。

故选D。

点睛:本题为分段的嵌套函数,则令,又原函数的值域性质可知有两个零点,及有解,则存在解,且,由图象可知,,且
,,所以,令,通过求导,可知的范
围是。

二、填空题(每题5分,满分20分,将答案填在答题纸上)
13. 已知双曲线经过点,其一条渐近线方程为,则该双曲线的标准方程为__________.
【答案】
【解析】由双曲线的渐近线方程设双曲线方程为 ,由点在双曲线上,有 ,所以 ,故双曲线方程为 .
14. 已知函数,若正实数满足,则的最小值为__________.。

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