【洛阳2021届高三一模】洛阳市2020-2021学年高三第一次统一考试 理数(高清含答案)
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2020-2021学年洛阳市第一高级中学高三英语模拟试题及答案第一部分阅读(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、D四个选项中选出最佳选项ADuring ancient times, children didn’t have smartphones, iPad or computers to entertain themselves. Instead, they came up with interesting games to play.★Stone ballsDuring the Qing Dynasty, kicking a stone ball around was a popular sport in the northern part of China, and it was often played in the winter to protect kids from the cold. Stones were carved into small balls and kicked along with feet. In 1999, the sport was included in the 6th National Ethnic Group Traditional Sports Meeting held in Beijing.★Flying kitesKites have quite a long history. The earliest kites were made of wood, instead of paper. Nowadays, the four most famous kites are the Beijing kite, Tianjin kite , Weifang kite and Nantong kite, of which each has distinctive features. The kite which resembles a swallow is a well-known Beijing style.★Hide-and-seekHide-and-seek is a traditional game for children, popular around the nation. There are two ways to play: covering a child’s eyes while other kids run around to tease(戏弄) him or, more commonly, participants hide and one child must try to find them.★Playing diabolosA diabolo is always made of wood or bamboo and has empty space in the center. By juggling(边抛边接) the diabolo on the rope, the high-speed spinning diabolos will make a sound like a whistle. Playing diabolos is an interesting folk game, especially popular in North China. Playing diabolos was also included in the first group of national intangible cultural heritage(非物质文化遗产).1.Why did ancient children often play stone balls in the winter?A.To practice their feet.B.To warm themselves.C.To train their skills.D.To relax themselves.2.Which kites are swallow-shaped?A.Weifang kites.B.Tianjin kites.C.Beijing kites.D.Nantong kites.3.Why does playing diabolos make a sound?A.Because the diabolo’s center is empty.B.Because the high-speed spinning diabolo is light.C.Because the diabolo is equipped with a whistle.D.Because ropes’ surface moves against the diabolo’s.BThere is an old Chinese proverb that states “One generation plants the trees; another gets the shade,” and this is how it should be with mothers and daughters. The relationship between a mother and a daughter is sometimes confusing. The relationship can be similar to friendship. However, the mother and daughter relationship has unique characteristics that distinguish it from a friendship. These characteristics include responsibilities and unconditional love, whichprecludemothers and daughters from being best friends.Marina, 27 years old, said, “I love spending time with my mom, but I wouldn’t consider her my best friend. Best friends don’t pay for your wedding. Best friends don’t remind you how they carried you in their body and gave you life! Best friends don’t tell you how wise they are because they have been alive at least 20 years longer than you.” This doesn’t mean that the mother and daughter relationship can’t be very close and satisfying. This generation of mothers and adult daughters has a lot in common, which increases the likelihood of shared companionship. Mothers and daughters have always shared the common experience of being homemakers, responsible for maintaining(保持) and passing on family values and traditions. Today contemporary mothers and daughters also share the experience of work and technology, which may bring them even closer together.Best friends may ormay not continue to be best friends, but for better or worse; the mother and daughter relationship is permanent, even if for some unfortunate reason they aren’t speaking. Sometimes this is not an equal relationship. Daughters don’t always feel responsible for their mother’s emotional well-being. But mothers never stop being mothers, which includes frequently wanting to protect their daughters and often feeling responsible for their happiness. The mother and daughter relationship is a relationship that is not replaceable by any other. Mothers always “trump(胜过)” friends.4. What does the underlined word “preclude” in paragraph 1 probably mean?A. differ.B. benefit.C. prevent.D. change.5. What can we learn from what Marina said?A. Best friends will not spend money on her wedding.B. Best friends will not remind her of important issues in life.C. Her mother is wiser on account of her age.D. Her mother is definitely not her best friend.6. Why can a mother and a daughter build a even closer relationship today?A. Because they share advanced technology with each other.B. Because they work together to support the whole family.C. Because they experience the same values and traditions.D. Because they have common experience in life and work.7. What is the text mainly about?A. How to build a good mother and daughter relationship.B. A mother-daughter relationship is irreplaceable.C. Mothers want to be daughters’ friends.D. A daughter is a mother’s best friend.CYour best friend that follows you around when the sun comes out - your shadow - doesn’t serve an important function like your heart or brain, but what if you could use shadows to create electricity? When using solar panels (电池板) that are powered by light, shadows can be boring because it means electricity can’t be created. However, researchers from the National University of Singapore have engineered a way to create power from the shadows present everywhere.A team of the university created a machine that can collect energy from shadows. It is created by placing a thin coating of gold onto silicon (硅). Like in a normal solar panel, when put in light, the silicon electrons (电子) become energized and the energized electrons then jump from the silicon to the gold. The voltage (电压) of the part of the machine that is placed in the light increases to the dark part and the electrons in the machine flow from high to low voltage. They are sent through an external circuit (外电路) creating a current that can be used to power another machine. The greater the contrast between light and dark, more energy is provided by the machine.The team isworking on improving the performance of the machine, borrowing approaches from solar panels to gather light. Increasing the amount of light the machines can receive allows them to better make use of shadows, as well as developing shadow energy collecting panels that can successfully gather from indoor lighting. The team is also researching the use of other materials other than gold to drop the price of the machine, meaningthey would be more cost effective and easier to apply in society.Shadows are present everywhere and perhaps one day in the future we will be able to collect energy from them by placing the shadow-effect energy machine around the world in places that have been considered unfit for solar panels to work, or indoors. “A lot of people think that shadows are useless,” Tan says, but “anything can be useful, even shadows.”8. What is Paragraph 1 mainly about?A. Your best friend always stays with you after the sunrise.B. The shadow has the same function as the heart and brain.C. Shadows can stop solar panels from creating electricity.D. Researchers have found a way to create power from shadows.9. What is the key working principle of the machine mentioned in the text?A. The silicon produces electricity when it is in the light.B. The gold produces power with the help of the silicon.C. The energized electrons flow from high to low voltage.D. An external circuit creates current using another machine.10. How does the team improve the performance of the machine?A. Using solar panels in the machine.B. Increasing the amount of light received.C. Developing light energy collecting panels.D. Bringing down the price of gold.11. Which of the following is the best place to apply the machine?A. A gym.B. A park.C. A farm.D. A playground.DSam, I say to myself as I start across the bridge, you must stop these thoughts and start thinking about what to do now that you have lost your falcon, Frightful.Life, my friend Ban do once said, is meeting problems and solving them whether you are an amoeba or a space traveller. I have a problem. I have to provide my younger sister Alice and myself with meat. Fish, nuts, and vegetables are good and necessary, but they don't provide enough fuel for the hard physical work we do. Although we have venison now, I can't always count on getting it. So far this year, our venison has been only road kill from in front of Mrs Strawberry's farm.I decide to take the longest way home, down the flood plain of the West Branch of Delaware to Spillkill, my own name for a fast stream that cascades down the south face of the mountain range I'm on. I need time to think. Perhaps Alice and I should be like the early Eskimos. We should walk, camp and hunt, and when the seasons change, walk on to new food sources. But I love my tree and my mountaintop.Another solution would be to become farmers, like the people of the Iroquois Confederacy who once lived here. They settled in villages and planted corm and squash, bush beans and berries. We already grow groundnuts in the damp soil and squash in the poor land. But the Iroquois also hunted game. I can't do that anymore.I'm back where I started from.Slowly I climb the Spillkill. As I hop from rock to rock beneath shady basswoods and hemlocks, I hear the cry of the red-tailed hawk who nests on the mountain crest. I am reminded of Frightful and my heart aches. I can almost hear her call my name, Cree, Cree, Cree, Car-ree.Maybe I can get her back if I beg the man who is in charge of the peregrines at the university. “But it's the law,” he would say. I could write to the president of the United States and ask him to make an exception of Alice and me. That won't work. The president swore to uphold the Constitution and laws of the United States when he took office.I climb on. I must stop thinking about the impossible and solve the problem of what to do now. I must find a new way to provide for us. Frightful is going to be in good hands at the university, and she will have young.I smile at the thought of little Frightfuls and lift my reluctant feet.When I am far above the river, I take off my clothes and moccasins and bathe in a deep, clear pool until I am refreshed and thinking more clearly. Climbing up the bank, I dress and sit down. I breathe deeply of the mountain air and try to solve my problem more realistically.12. What does this excerpt main describe?A. Delicate mental activities.B. Unique story environment.C. Everchanging story events.D. Complicated character relationship.13. What is Sam's first worry?A. How to get back quicklyB. How to get enough venison.C. How to ensure the safety of Frightful.D. How to provide meat for Alice and himself.14. What do we know about Frightful?A. He left Sam and Alice due to lack of food.B. He helped Sam hunt before being taken away.C. He is living with the red-tailed hawk happily.D. He has given birth to babies in the university.15. Which of the following can best describe Sam?A. Humorous.B. Aggressive.C. Responsible.D. Unrealistic.第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
洛阳市2021—2022学年高中三年级第一次统一考试数学试卷(理)本试卷分第1卷(选择题)和第Ⅱ卷(非选择题)两部分.第1卷1至2页,第Ⅱ卷3至4页.共150分。
考试时间120分钟。
第Ⅰ卷(选择题,共60分)注意事项:1.答卷前,考生务必将自己的姓名、考号填写在答题卡上. 2.考试结束,将答题卡交回.一、选择题:本大题共12小题,每小题5分,共60分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.已知复数z =sin 2+icos 2,则|z |=A .4B .3C .2D .12.已知全集为R ,集合A ={x |-2<x <l},集合B ={x |-x 2+x <0}.则A ∪(∁R B )=A .(-2,1]B .(-1,1]C .(-∞,-2)∪[1,+∞)D .(-∞,0]∪(1,+∞)3.某种游戏棋盘形状如图,已知大正方形的边长为12.每个小正方形的边长均为2.在游戏棋盘上随机取一点,则该点取自小正方形以外的概率为A .89B .79C .56D .3536.4.已知命题p : x ∈R ,x 2+x +1>0;命题q :若a >b ,则1a <1b.下列命题为真的是A .(¬p )∨q ∧B .(¬p )∧(¬q )C .p )∧qD .p ∨q 5.若右面框图所给的程序运行结果为28,那么判断框中应填入的关于k 的条件是A .k ≥6B .k ≥7C .k ≥8D .k ≥96.已知a = 1-1x d x ,则(2x +a -1)5的展开式中x 3的系数为A .40B .-40C .80D .-80 7.已知函数f (x )=sin(ωx +2π3)在[-π,π]上的图象如图所示,现将其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,则g (x )=A .sin(3x +2π3)B .sin(34x +2π3)C .sin(32x +2π3)D .sin(83x +2π3)8.新冠疫情期间,某医学院将6名研究生安排到本市四家核酸检测定点医院进行调研,要求每家医院至少去1人,至多去2人,且其中甲乙二人必须去同一家医院,则不同的安排方法有A .72种B .96种C .144种D .288种9.已知△ABC 中,AB =5,AC =4,则当函数f (A )=sin(A +π6)+3cos(A +π6)-cos 2A 取得最大值时,BC =k =10, S=1 开始S=S+k k =k -1结束输出S 是 否A .4B .21C .41D .21410.如图,AB ,CD 分别是圆柱上、下底面圆的直径,且AB ⊥CD .O 1,O 分别为上、下底面圆心,若圆柱的轴截面为正方形,且三楼锥A -BCD 的体积为43,则该圆柱的侧面积为A .9πB .10πC .12πD .14π11.已知双曲线x 2a 2-y 2b 2=1(a >0,b >0)的左、右焦点分别为F 1,F 2,点A 在双曲线上且AF 1→•AF 2→=0,若△AF 1F 2的内切圆的半径为(3-2)b ,则双曲线的离心率为 A .3+ 2 B .3+1 C . 3 D . 212.已知函数f (x )=x a -a ln x ,g (x )=e x -x (a >0),若存在x ∈(1,e 2)时,f (x )≤g (x )成立,则实数a 的最大值是A .1B .eC .e 22D .e 2第Ⅱ卷(非选择题,共90分)二、填空题:本题共4小题,每小题5分,共20分。
河南省洛阳市2021—2022学年高中三年级第一次统一考试地理试卷本试卷分第Ⅰ卷(选择题)和第Ⅱ卷(非选择题)两部分,共100分,考试时间为90分钟。
第Ⅰ卷(选择题,共60分)注意事项:1.答卷前,考生务必将自己的姓名、考号填写在答题卡上。
2.考试结束,将答题卡交回。
一、单项选择题:(每小题2分,共60分。
)2021年11月7日20时28分,神舟十三号航天员翟志刚、王亚平先后从天和核心舱节点舱成功出舱。
王亚平的出舱标志着中国女航天员首次实现“太空漫步”,她身着的新舱外服也在太空中首次亮相。
图1为在北京航天飞行控制中心拍摄的神舟十三号航天员王亚平(右)结束出舱任务的照片,据此完成1-2题。
图11.航天员的舱外航天服具有的主要功能有①隔绝高低温②保持压力平衡③防强辐射④减轻失重感A.①②③B.①③④C.②③④D.①②④2.航天员出舱时不能观察到的是A.悬浮在宇宙中的蔚蓝色地球B.黑色天幕上无数明亮的星星C.太阳照射下的明亮船体D.划过天幕的众多流星国庆节期间,湖北某校研学小组到学校周边的山地进行考察,在出发前他们专门学习了夏季去山区旅游的相关安全知识,并设计了登山线路。
在山顶上他们领略了优美的湖光山色,当地人告诉他们,而季M湖湖水经常外泄。
图2示意他们绘制的该山等高线地形图和登山线路。
据此完成3-5题。
3.M湖湖水上涨外泄处的海拔可能是A.1280米B.1520米C.1480米D.1620米4.当研学小组到达②处时,如果突遇湖水大量外泄,最佳的逃生方向是A.东北B.正北C.东南D.正南5.登山线路上最早看到日出的是A.①地B.②地C.③地D.④地九九消寒图是我国民间传统文化中冬季“数九”计算日期的一种方法。
“日冬至,画素梅一枝,为瓣八十有一,日染一瓣,瓣尽而九九出,则春深矣,日九九消寒图。
”图3为一位同学某日涂染的消寒图,据此完成6-7题。
6.自冬至涂染开始,至消寒图如图3所示期间,洛阳A.气温降至全年最低B.日出方位逐渐偏南C.白昼浙短黑夜渐长D.正午日影逐渐变短7.当整个消寒图涂染全部完成时A.青海湖畔油菜花次第开放B.黄河上游可能出现凌汛C.三江平原进入春耕时节D.华北地区准备收割小麦蒸发皿蒸发量是指在蒸发皿中一直有水状态下测得的蒸发量,它反映陆地蒸发的能力,代表地面最大理论蒸发量。
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)A.Below is a housing for students going to London.University accommodation (住所) officesMany university accommodation offices have their own list of registered landlords (房东). Others also provide information on accommodation agencies and other housing organizations. The advantage of using your university accommodation is that you can get support if you have a problem. The disadvantage is that they are unlikely to have enough registered landlords to house all their students.Property papers:Loot and RentingLoot is an important source (来源) of information about private housing for co-renters. The offers are from private landlords, agencies and individuals looking for other co-renters. They also have a website:.The advantage of using Loot is that there are some excellent bargains. The disadvantage is that there is no quality control over the offers.Renting is another useful paper. The offers in this paper are mainly from accommodation agencies. Their website is at .Accommodation agenciesThe majority of rented accommodation in London is probably advertised through accommodation agencies. The advantage of using accommodation agencies is that you will have access to a large number of accommodations. A good agent will listen to your requirements and can save you time in looking for the right accommodation. The disadvantageis that they will make a range of charges to potential renters.NoticeboardsAround the universities you will find a number of noticeboards where offers of accommodation will be posted. These will either be from landlords or from students. Some universities will also have online noticeboards where students can advertise to other students. Advertisements from students can be an excellent way to find accommodation. However, advertisements from landlords can be problematic.Word of mouthSome of the best housing in London is never advertised but is passed on from one group of students to another by word of mouth. It might be that you can find out about good offers from final year students. However, don’t suppose that just because you have found out about housing from a friend it is necessarily going to be better than that found through any other source.FamilyFaced with the very high rents charged in London, some students and their parents will consider buying as an alternative. In some cases this might be a good choice.21. What is the advantage of using Loot?A. It has more offers from accommodation agencies than Renting.B. It gives you personal information about other co-renters.C. Their website is designed mainly for students.D. there are some good bargains.22. A good agent can help you ________.A. know more peopleB. find cheap accommodationC. get the right accommodation quicklyD. get free information about most accommodations23. The information passed on by word of mouth is important because________.A. it is better than that found through any other sourceB. it helps you find some of the best housing never advertisedC. the final year students always offer better informationD. the landlords have little valuable informationB(命题人:张若男)Driving to a friend’s house on a recent evening, I was attracted by the sight of the full moon rising just above my friend’s roof-tops. I stopped to watch it for a few moments, thinking about what a pity it was that most citizens, myself included, usually miss sights like this because we spend most of our lives indoors.My friend had also seen it. He grew up living in a forest in Europe, and the moon meant a lot to him then. It had touched much of his life.I know the feeling. Last December I took my seven-year-old daughter to the mountainous jungle of northern India with some friends. We stayed in a forest rest-house with no electricity or running hot water. Our group had campfires outside every night, and indoors when it was too cold outside. The moon grew to its fullest during our trip. Between me and the high mountains lay three or four valleys. Not a light shone in them and not a sound could be heard. It was one of the quietest places I have ever known, a bottomless well of silence. And above mewas the full moon, which struck me deeply.Today our lives are filled with glass, metal, plastic and fiber-glass. We have televisions, cellphones, papers, electricity, heaters and ovens and air-conditioners, cars, computers.Struggling through traffic that evening at the end of a tiring day, most of which was spent in doors, I thought that before long I would like to live in a small cottage. There I will grow vegetables and read books and walk in the mountains, and perhaps write, but not in anger. I may be come an old man there, and wear the bottoms of my trousers rolled and measure out my life in coffee spoons. But I will be able to walk o utside on a cold silent night and touch the moon.24.The best title for the passage would be ________.A. The pleasures of modern lifeB. Touched by the moonC. A bottomless well of silenceD. Break away from modern life25.What impressed the writer most in the mountainous jungle of northern India?A. No modern equipment.B. Complete silence.C. The nice moonlight.D. The high mountains.26. Modern things (Paragraph 4) are mentioned mainly to ________.A. show that the writer likes city life very muchB. tell us that people greatly benefit from modern lifeC. explain that people have less chances to enjoy natureD. show that we can also enjoy nature at home through them27.The author wrote the passage to ________.A. express the feeling of returning to natureB. show the love for the moonlightC. advise modern people to learn to liveD. want to communicate longing for modern lifeCIt has often been suggested that the ocean, rather than space ,is the true final frontier. From the extremely high pressure that threatens human lives to unknown geography that can injure people and machines alike, various things make sending human explorers hazardous. The deepest section of the ocean is the Marianas Trench, which begins at 20,000 feet. It has points where the depth approaches seven miles and the pressure reaches eight tons per square inch. That’s why the Marianas Trench remains largely unexplored to this day.Even knowing about all of the difficulties, however, some scientists feel the draw of the ocean’s depths. The environment, unfriendly though it may be to man, is friendly to others, allowing for the development of quite a few creatures not found anywhere else on the planet. The first exploration of the Marianas Trench’s floor took place in 1960. Since then, the cost of sending people back has been seen as too great.The goal, then, has been to find a way to learn about this frontier without risking the lives of explorers. One way that scientists have discovered new information is through the use of sonar. As sonar technology — a sound-based method of determining surroundings —hasimproved, scientists have been able to get more accurate maps of the ocean’s floor.Another method of exploration that has become more common in recent years is to use machines that have no people working inside them. These include underwater cameras and robots. The latter have become increasingly common in recent years.Although most of the robots used so far have been attached to a larger device with people aboard, the day when the robots can move independently may not be far off. As technology is being advanced, it seems quite likely that automatic robots will become more competent ocean floor explorers than humans.28. The underlined word “hazardous” in Paragraph 1 probably mean “_______”A. simpleB. riskyC. necessaryD. possible29. According to the passage, what do we know about the Marianas Trench?A. It has an average depth of 20,000 feet.B. It has become easy to send humans into it.C. There are many unique animals living in it.D. Many successful explorations of it have been made.30. Which of the following is most widely used to learn about this frontier?A. Sonar technology.B. Manned exploration.C. Underwater cameras.D. Underwater robots.31. What is the author’s attitude toward robotic exploration of the Marianas Trench?A. Optimistic.B. Doubtful.C. Curious.D. Worried.D(命题人:方利红)When social media first gained attention, I heard many people say online connectionscouldn’t possibly be real friends. But now the majority of the people I know consider at least some of their online friends to be like extended family, which made me wonder--- does social media actually encourage people to connect “in real life”?One example of online life translating into real-life interaction happens on Mashable’s Social Media Day, when thousands of people attend in-person meet-ups to celebrate the power of online connections. Another example is location-based apps that help users connect face to face by allowing them to see who else has checked in at the same store, restaurant, or party--- or even who is living in a city they plan to visit. They might then decide to seek each other out “in real life”.A Pew Internet and American Life Project (PIALA)report found that people using social networking sites have more close relationships and receive more support than others. They are also more likely to reconnect with old friends and keep up with those they are already close to. Other research shows that social media may also deepen what could otherwise be passing relationships. “What I find most interesting is that I’ve co nsistently seen that students who start a course being more introverted and not speaking up during class discussions become more outgoing and participate more when encouraged to commun icate through social media with their professors and their classmates,” said Dr. Rey Junco.However, if social media does increase the possibilities of real-life interaction, it can also sometimes complicate it. When fans of social media meet face to face, their computers and mobile devices may actually make the meeting less productive. Instead of looking at each other, they may be glued to their screens!32. The examples mentioned in Paragraph 2 are mainly used to show .A. it is necessary to make friends in real lifeB. it is inspiring to make friends whenever possibleC. the positive effects of social media have on peopleD. the good effects of Social Media Day and location-based apps have on people33. According to the PIALP report, online connections .A. can help people promote original relationshipsB. can help people become independentC. should keep pace with the timesD. should get more support from others34. The underlined word “introverted” in Paragraph 4 probably means “”.A. trustworthy and loyalB. unsocial and quietC. patient and modestD. nervous and disorganized35. What can we learn from the last paragraph?A. A friend in need is a friend indeed.B. Actions speak louder than words.C. Easier said than done.D. Everything is a double-edged sword.第二节(共5小题;每小题2分,满分10分)(命题人:张若男)Speed is an essential skill in the Internet age. We skim over articles and e-mails to try to grasp key words and the essential meaning of a certain text. Attacked with information fromour electronic devices, it would be impossible to cope if we read word by word, line by line. 36A recent story from The Wall Street Journal reported on a book club in Wellington, New Zealand, where members meet in a cafe and turn off their smart phones. They sink into cozy chairs and read in silence for an hour.Unlike traditional book clubs, the point of the slowing reading club isn’t exchanging ideas about a certain book. 37 According to the journal, the Wellington book club is just one example of a movement initiated by book lovers who miss the old-fashioned way of reading before the Internet and smart phones.Slow readers, such as The Atlantic’s Maura Kelly, say a regular reading habit sharpens the mind, improves concentration, reduces stress levels. 38Slow reading means a return to an uninterrupted pattern, in a quiet environment free of distractions. 39 “ You can squeeze in that half hour pretty easily if only dur ing your free moments—whenever you find yourself automatically firing up your laptop to check your favorite site, or scanning Twitter for something to pass the time— you pick up a meaning work of literature,” Kelly said. “40 Kindles make books like War and Peace less heavy, not less substantive(真实的), and also ensure you will never lose your place.”A.Reach for your e-reader, if you like.B.Traditional book clubs are disappearing.C.But some of these benefits have been backed up by science.D.But a new trend calls on people to enjoy reading slowly.E.Aim for 30 minutes a day, advises Kelly from The Atlantic.F.It is to get away from electronic devices and r ead in a quiet, relaxed environment.G. Both speed-reading and slow-reading are greatly needed in reading articles and e-mails.第三部分英语知识运用(共两节,满分45分)第一节完形填空(共20小题;每小题1.5分,满分30分)(命题人:李珍)However objective we believe ourselves to be, most of us do not judge a product only on the basis of its advantages, 41 its quality, value or style before making a decision. 42 , we are easily influenced by the people around us.There is nothing 43 with this. It is probably a smarter way to make decisions than relying on only our own 44 . But it does make life 45 for companies. They have long understood that groups of friends and relatives 46 to buy the same products, but understanding the 47 has been tricky. Is it because they are so similar with 48 to how much money they 49 and what television ads they watch that they 50 arrive at the same decision?Or do they 51 one another, perhaps 52 envy or perhaps because they have shared information about the products?Research in Finland recently found overwhelming 53 that neighbours have a big influence on buying 54 . When one of a person’s ten nearest neighbours bought a car, the 55 that that person would buy a car of the 56 brand during the next week and a half 57 by 86 percent. The researchers argued that it was not just a matter of envy. Used cars seemed to attract neighbours even more. This 58 that people were not trying to keep up with their neighbours, they were keen to 59 them. Since second-hand cars are less reliable, a(n) 60 of one can strongly influence a buying decision.41. A. recognizing B. considering C. appreciating D.introducing42. A. Otherwise B. However C. Instead D. Therefore43. A. normal B. funny C. scientificD. wrong44. A. opinions B. solutions C. actionsD. traditons45. A. happy B. hard C. fair D. simple46. A. fail B. agree C. pretendD. tend47. A. problems B. rules C. reasonsD. methods48. A. connection B. regard C. relationD. concern49. A. borrow B. make C. wasteD. need50. A. madly B. immediately C. hardlyD. independently51. A. help B. pay C. copyD. call52. A. out of B. for C. as toD. about53. A. excuses B. results C. commentD. evidence54. A. power B. decisions C. time D. approaches55. A. choices B. challenges C. chances D. changes56. A. best B. worst C. sameD. different57. A. raised B. rose C. enlarged D. extended58. A. suggested B. promised C. announced D. predicted59. A. argue with B. care about C. live with D. learn from60. A. effort B. permission C. recommendation D. feeling第二节(共10小题;每小题1.5分,满分15分)(命题人:刘亚利)The teacher who did the most to encourage me was, __61__it happens, my aunt. She was Myrtle C. Manigault, __62__ wife of my mother’s brother Bill. She taught me in second grade at all-black Summer School in Camden, New Jersey.During my childhood and youth, Aunt Myrtle encouraged me to develop every aspect of mypotential, without regard for what__63__ (consider) practical and impossible for black females.I liked to sing; she listened to my voice and pronounced __64__ good. She took me to the theatre—not jus t children’s theatre __65__ adult comedies and dramas—and her faith __66__I could appreciate adult plays was not disappointed.Most important, perhaps, Aunt Myrtle provided my first opportunity to write for __67__(publish). A writer herself for one of the black newspapers, she suggested my name __68__ the editor as a “youth columnist”. My column, __69__(begin)when I was fourteen, was supposed __70__ (cover)teenage social activities—and it did—but it also gave me the freedom to write on many other subjects.第四部分写作(共两节,满分35分)第一节短文改错(共10小题;每小题1分,满分10分)(命题人:刘亚利)假定英语课上老师要求同桌之间交换修改作文, 请你修改你同桌写的以下作文。
洛阳市2020——2021学年高中三年级第一次统一考试历史试卷本试卷分第I卷(选择题)和第II每(非选择题)两部分,全卷共6页,共100分,考试时间为90分钟。
第I卷(选择题,共48分)注意事项:1.答第I卷前,考生务必将自己的姓名、考号填写在答题卡上。
2.每小题选出答案后,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,不能答在试题卷上。
3.考试结束后,将答题卡交回。
一、选择题(本大题共24小题,每小题2分,共48分。
每小题只有一个答案是正确答案。
)1.春秋时期“学在官府”的局面被打破,原来由贵族垄断的文化学术开始向社会下层扩散,下移于民间。
这一现象A.促进了官僚政治的产生B.加速分封制的解体C.催生了新兴阶层的出现D.推动了文化的活跃2.战国末期,荀子曾将当时的各种学说一一驳斥,认为战国混乱的原因之一是“百家异说",要社会安定就要做到“天下无二道,圣人无两心”。
荀子的主张A.意在突出儒家的地位B.奠定了法家的思想基础C.顺应政治发展的潮流D.改变了社会动荡的局面3.东汉灵帝嘉平四年(公元175年),议郎蔡邕建议朝廷在太学门外树立刻有《周易》、《尚书》、《春秋》、《公羊传》、《论语》等经书的石碑。
历时8年,全部刻成。
这些碑文成为当时读书人的经典,很多人争相抄写。
这一措施A.表明儒家经典已成为国家教科书B.推动了印刷术的创新发展C.促进了各地学术文化的交流发展D.利于巩固儒学的统治地位4.有学者把唐代的藩镇根据分布特点大致分为河朔型、中原型、边疆型、东南型等,其中河朔型藩镇最基本的特点是藩帅不由中央派遣而由本镇拥立,如魏博、成德、卢龙三镇节度使前后凡五十七人,唐廷所任者仅4人,其余都是父死子继、兄终弟及或偏裨擅立。
这种藩镇A.导致唐朝对地方的控制力削弱B.导致安史之乱的爆发C.形成源于地方经济实力的强大D.使唐朝迅速走向灭亡5.苏轼《书鄢陵王主薄所画折枝二首》中说:“论画以似形,见与儿童邻。
2024届河南省洛阳市高三第一次统一考试全真演练物理试题(基础必刷)学校:_______ 班级:__________姓名:_______ 考号:__________(满分:100分时间:75分钟)总分栏题号一二三四五六七总分得分评卷人得分一、单项选择题(本题包含8小题,每小题4分,共32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)(共8题)第(1)题图示为一种自动测定油箱内油面高度的装置,装置中金属杠杆的一端接浮标(浮标与杠杆绝缘),另一端的触点P接滑动变阻器R,油量表由电流表改装而成。
当汽车加油时,油箱内油面上升过程中,下列说法正确的是( )A.电路中电流减小B.两端电压减小C.整个电路消耗的功率增大D.电源输出功率一定增大第(2)题截至2021年12月31日,中国大陆运行核电机组共53台,运行核电机组累计发电量占全国累计发电量的5.02%。
核电站发电主要通过核裂变放出能量,下列核反应方程属于核裂变的是( )A.B.C.D.第(3)题在如图所示的电路中,理想变压器的原、副线圈的匝数比为,在a、b端输入电压为U0的正弦交流电,R1为定值电阻,调节电阻箱R2,当R2=8R1时,电压表、电流表的示数分别为U、I,则下列说法正确的是( )A.B.C.D.第(4)题在高速公路的水平弯道,若直线道路与转弯的圆曲线(曲率半径一定)道路直接连接,则弯道处存在曲率半径突变。
为提高旅客乘车经过弯道时的舒适度,通常设计用一段缓和曲线将直线与圆曲线连接,实现曲率半径的逐渐过渡。
假如汽车以恒定的速率经过弯道,因弯道有了缓和曲线的连接,则乘客乘车如图从P到Q的过程中( )A.惯性将减小B.向心加速度是逐渐减小的C.受到的合外力是逐渐增大的D.合外力对乘客做正功第(5)题对于分子动理论和物体内能的理解,下列说法正确的是( )A.温度高的物体内能一定大B.外界对物体做功,物体内能一定增加C.当分子间的距离增大时,分子间的作用力就一直减小D.悬浮微粒的布朗运动可以间接地反映液体分子运动的无规则性第(6)题如图,沿水平直轨道运行的地铁车厢内,有一拉环(可视为质点)用轻绳与套于水平杆中的固定限位块相连,某段时间内拉环与竖直方向夹角始终为θ。
河南省洛阳市尖子生高三(上)第一次联考数学试卷(理科)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.(5分)设集合,B={x|lnx<0},则∁R(A∩B)等于()A.{x|x≥0}B.{x|x≥1}C.R D.{0,1}2.(5分)已知复数z满足z(1﹣i)2=1+i (i为虚数单位),则|z|为()A.B.C.D.13.(5分)如图,圆O:x2+y2=π2内的正弦曲线y=sinx与x轴围成的区域记为M (图中阴影部分),随机往圆O内投一个点A,则点A落在区域M内的概率是()A.B.C.D.4.(5分)一个几何体的三视图如图所示,则该几何体的体积为()A.2 B.1 C.D.5.(5分)设a=log36,b=log510,c=log714,则()A.c>b>a B.b>c>a C.a>c>b D.a>b>c6.(5分)如图的程序框图所描述的算法,若输入m=209,n=121,则输出的m的值为()A.0 B.11 C.22 D.887.(5分)在等比数列{a n}中,a2,a16是方程x2+6x+2=0的根,则的值为()A.B.C.D.或8.(5分)已知点O是锐角三角形ABC的外心,若(m,n∈R),则()A.m+n≤﹣2 B.﹣2≤m+n<﹣1 C.m+n<﹣1 D.﹣1<m+n<09.(5分)设双曲线C:的右焦点为F,过F作渐近线的垂线,垂足分别为M,N,若d是双曲线上任一点P到直线MN的距离,则的值为()A.B.C.D.无法确定10.(5分)已知球O与棱长为4的正四面体的各棱相切,则球O的体积为()A.B.C.D.11.(5分)已知函数f(x)=sin(sinx)+cos(sinx),x∈R,则下列说法正确的是()A.函数f(x)是周期函数且最小正周期为πB.函数f(x)是奇函数C.函数f(x)在区间上的值域为D.函数f(x)在是增函数12.(5分)已知函数f(x)=(ax+lnx)(x﹣lnx)﹣x2有三个不同的零点x1,x2,x3(其中x1<x2<x3),则的值为()A.1﹣a B.a﹣1 C.﹣1 D.1二、填空题(每题5分,满分20分,将答案填在答题纸上)13.(5分)已知x,y满足条,则z=的取值范围是.14.(5分)已知随机变量X~B(2,p),Y~N(2,σ2),若P(X≥1)=0.64,P (0<Y<2)=p,则P(Y>4)=.15.(5分)已知(1+ax+by)5(a,b为常数a∈N*,b∈N*)的展开式中不含字母x的项的系数和为243,则函数,的最小值为.16.(5分)已知数列{a n}满足na n+2﹣(n+2)a n=λ(n2+2n),其中a1=1,a2=2,若a n<a n+1对∀n∈N*恒成立,则实数λ的取值范围是.三、解答题(本大题共5小题,共70分.解答应写出文字说明、证明过程或演算步骤.)17.(12分)如图,在△ABC中,点P在BC边上,∠PAC=60°,PC=2,AP+AC=4.(Ⅰ)求∠ACP;(Ⅱ)若△APB的面积是,求sin∠BAP.18.(12分)如图1,在直角梯形ABCD中,AD∥BC,AB⊥BC,BD⊥DC,点E 是BC边的中点,将△ABD沿BD折起,使平面ABD⊥平面BCD,连接AE,AC,DE,得到如图2所示的几何体.(Ⅰ)求证:AB⊥平面ADC;(Ⅱ)若AD=1,二面角C﹣AB﹣D的平面角的正切值为,求二面角B﹣AD ﹣E的余弦值.19.(12分)随着移动互联网的快速发展,基于互联网的共享单车应用而生,某市场研究人员为了了解共享单车运营公司M的经营状况,对该公司最近六个月内的市场占有率进行了统计,并绘制了相应的折线图.(Ⅰ)由折线图可以看出,可用线性回归模型拟合月度市场占有率y与月份代码x之间的关系,求y关于x的线性回归方程,并预测M公司2017年4月份(即x=7时)的市场占有率;(Ⅱ)为进一步扩大市场,公司拟再采购一批单车.现有采购成本分别为1000元/辆和1200元/辆的A、B两款车型可供选择,按规定每辆单车最多使用4年,但由于多种原因(如骑行频率等)会导致车辆报废年限不相同.考虑到公司运营的经济效益,该公司决定先对两款车型的单车各100辆进行科学模拟测试,得到两款单车使用寿命频数表如下:报废年限1年2年3年4年总计车型A20353510100B10304020100经测算,平均每辆单车每年可以带来收入500元,不考虑除采购成本之外的其他成本,假设每辆单车的使用寿命都是整数年,且以频率作为每辆单车使用寿命的概率.如果你是M公司的负责人,以每辆单车产生利润的期望值为决策依据,你会选择采购哪款车型?(参考公式:回归直线方程=x+,其中=,=﹣)20.(12分)如图,点F是抛物线τ:x2=2py (p>0)的焦点,点A是抛物线上的定点,且=(2,0),点B,C是抛物线上的动点,直线AB,AC斜率分别为k1,k2.(I)求抛物线τ的方程;(Ⅱ)若k2﹣k1=2,点D是点B,C处切线的交点,记△BCD的面积为S,证明S 为定值.21.(12分)已知函数f(x)=(x3﹣6x2+3x+t)e x,t∈R.(1)若函数y=f(x)有三个不同的极值点,求t的值;(2)若存在实数t∈[0,2],使对任意的x∈[1,m],不等式f(x)≤x恒成立,求正整数m的最大值.请考生在22、23两题中任选一题作答,如果多做,则按所做的第一题记分.[选修4-4:坐标系与参数方程]22.(10分)在平面直角坐标系xOy中,直线l的参数方程为(t为参数),以坐标原点为极点,x轴的正半轴为极轴建立极坐标系,曲线C的极坐标方程为ρ2=,且直线l经过曲线C的左焦点F.(I )求直线l的普通方程;(Ⅱ)设曲线C的内接矩形的周长为L,求L的最大值.[选修4-5:不等式选讲]23.已知函数f(x)=|x+1﹣2a|+|x﹣a2|,g(x)=x2﹣2x﹣4+(Ⅰ)若f(2a2﹣1)>4|a﹣1|,求实数a的取值范围;(Ⅱ)若存在实数x,y,使f(x)+g(y)≤0,求实数a的取值范围.2017-2018学年河南省洛阳市尖子生高三(上)第一次联考数学试卷(理科)参考答案与试题解析一、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.(5分)设集合,B={x|lnx<0},则∁R(A∩B)等于()A.{x|x≥0}B.{x|x≥1}C.R D.{0,1}【解答】解:由A中的不等式解得:x>1或x<0,即A={x|x>1或x<0},由B中的不等式解得:0<x<1,即B={x|0<x<1},则A∩B=∅则∁R(A∩B)=R故选:C.2.(5分)已知复数z满足z(1﹣i)2=1+i (i为虚数单位),则|z|为()A.B.C.D.1【解答】解:由z(1﹣i)2=1+i,得,∴|z|=.故选:B.3.(5分)如图,圆O:x2+y2=π2内的正弦曲线y=sinx与x轴围成的区域记为M (图中阴影部分),随机往圆O内投一个点A,则点A落在区域M内的概率是()A.B.C.D.【解答】解:构成试验的全部区域为圆内的区域,面积为π3正弦曲线y=sinx与x轴围成的区域记为M,根据图形的对称性得:面积为S=2∫0πsinxdx=﹣2cosx|0π=4,由几何概率的计算公式可得,随机往圆O内投一个点A,则点A落在区域M内的概率P=故选B.4.(5分)一个几何体的三视图如图所示,则该几何体的体积为()A.2 B.1 C.D.【解答】解:由图可知该几何体是一个四棱锥其底面是一个对角线为2的正方形,面积S=×2×2=2高为1则V==故选C5.(5分)设a=log36,b=log510,c=log714,则()A.c>b>a B.b>c>a C.a>c>b D.a>b>c【解答】解:因为a=log36=1+log32,b=log510=1+log52,c=log714=1+log72,因为y=log2x是增函数,所以log27>log25>log23,∵,,所以log32>log52>log72,所以a>b>c,故选D.6.(5分)如图的程序框图所描述的算法,若输入m=209,n=121,则输出的m 的值为()A.0 B.11 C.22 D.88【解答】解:当m=209,n=121,m除以n的余数是88此时m=121,n=88,m除以n的余数是33此时m=88,n=33,m除以n的余数是22此时m=33,n=22,m除以n的余数是11,此时m=22,n=11,m除以n的余数是0,此时m=11,n=0,退出程序,输出结果为11,故选:B.7.(5分)在等比数列{a n}中,a2,a16是方程x2+6x+2=0的根,则的值为()A.B.C.D.或【解答】解:等比数列{a n}的公比设为q,a2,a16是方程x2+6x+2=0的根,可得a2a16=2,即有a12q16=2,即有a92=2,则的值为a9=±.故选:D.8.(5分)已知点O是锐角三角形ABC的外心,若(m,n∈R),则()A.m+n≤﹣2 B.﹣2≤m+n<﹣1 C.m+n<﹣1 D.﹣1<m+n<0【解答】解:∵O是锐角△ABC的外心;∴O在三角形内部,不妨设锐角△ABC的外接圆的半径为1,则m<0,n<0;∵(m,n∈R),∴=m2+n2+2mn•,设向量夹角为θ,则:1=m2+n2+2mncosθ<m2+n2+2mn=(m+n)2;∴m+n<﹣1,或m+n>1(舍去);∴m+n<﹣1.故选:C9.(5分)设双曲线C:的右焦点为F,过F作渐近线的垂线,垂足分别为M,N,若d是双曲线上任一点P到直线MN的距离,则的值为()A.B.C.D.无法确定【解答】解:双曲线C的方程:中a=4,b=3,c==5,右焦点为F(5,0),相应的渐近线:y=±x,M在直线y=x上,N在直线y=﹣x上,设直线MF的斜率为﹣,其方程为:y=﹣(x﹣5),设M(t,t),代入直线MF的方程,得:t=﹣(t﹣5),解得:t=,即M(,),由对称性可得N(,﹣),直线MN方程为x=,设P(m,n),可得﹣=1,即为n2=(m2﹣16),则|PF|===|5m﹣16|,则==.故选:B.10.(5分)已知球O与棱长为4的正四面体的各棱相切,则球O的体积为()A.B.C.D.【解答】解:将正四面体ABCD,补成正方体,则正四面体ABCD的棱为正方体的面上对角线.∵正四面体ABCD的棱长为4∴正方体的棱长为2∵球O与正四面体的各棱都相切,∴球O的直径为正方体的棱长2,则球O的体积V==.故选:A.11.(5分)已知函数f(x)=sin(sinx)+cos(sinx),x∈R,则下列说法正确的是()A.函数f(x)是周期函数且最小正周期为πB.函数f(x)是奇函数C.函数f(x)在区间上的值域为D.函数f(x)在是增函数【解答】解:f(x)=sin(sinx)+cos(sinx)=sin(sinx+),∵f(π+x)==,不满足对任意实数x 恒有=,故A错误;∵f(﹣x)=,不满足对任意实数x恒有=﹣,故B错误;当x∈时,sinx∈[0,1],sinx+∈[,],∴sin(sinx+)∈[],则sin(sinx+)∈[1,],故C正确;当x∈时,sinx∈[,1],sinx+∈[,],而∈[,],则函数f(x)在上不是单调函数,故D错误.故选;C.12.(5分)已知函数f(x)=(ax+lnx)(x﹣lnx)﹣x2有三个不同的零点x1,x2,x3(其中x1<x2<x3),则的值为()A.1﹣a B.a﹣1 C.﹣1 D.1【解答】解:令f(x)=0,分离参数得a=,令h(x)=,由h′(x)==0,得x=1或x=e.当x∈(0,1)时,h′(x)<0;当x∈(1,e)时,h′(x)>0;当x∈(e,+∞)时,h′(x)<0.即h(x)在(0,1),(e,+∞)上为减函数,在(1,e)上为增函数.∴0<x1<1<x2<e<x3,a==,令μ=,则a=﹣μ,即μ2+(a﹣1)μ+1﹣a=0,μ1+μ2=1﹣a<0,μ1μ2=1﹣a<0,对于μ=,μ′=则当0<x<e时,μ′>0;当x>e时,μ′<0.而当x>e时,μ恒大于0.画其简图,不妨设μ1<μ2,则μ1=,μ2==μ3=,=(1﹣μ1)2(1﹣μ2)(1﹣μ3)=[(1﹣μ1)(1﹣μ2)]2=[1﹣(1﹣a)+(1﹣a)]2=1.故选:D.二、填空题(每题5分,满分20分,将答案填在答题纸上)13.(5分)已知x,y满足条,则z=的取值范围是[3,9] .【解答】解:根据约束条件画出可行域,∵设k==1+,整理得(k﹣1)x﹣2y+k﹣3=0,由图得,k>1.设直线l0=(k﹣1)x﹣2y+k﹣3,当直线l0过A(0,3)时l0最大,k也最大为9,当直线l0过B(0,0))时l0最小,k也最小为3.故答案为:[3,9].14.(5分)已知随机变量X~B(2,p),Y~N(2,σ2),若P(X≥1)=0.64,P (0<Y<2)=p,则P(Y>4)=0.1.【解答】解:∵随机变量X~B(2,p),Y~N(2,σ2),P(X≥1)=0.64,∴P(X≥1)=P(X=1)+P(X=2)==0.64,解得p=0.4,或p=1.6(舍),∴P(0<Y<2)=p=0.4,∴P(Y>4)=(1﹣0.4×2)=0.1.故答案为:0.1.15.(5分)已知(1+ax+by)5(a,b为常数a∈N*,b∈N*)的展开式中不含字母x的项的系数和为243,则函数,的最小值为2.【解答】解:(1+ax+by)5(a,b为常数a∈N*,b∈N*)的展开式中不含字母x 的项的系数和为243,∴(1+b)5=243,解得b=2;时,∴x+∈[,],∴sinx+cosx=sin(x+)∈[1,];∴函数===(sinx+cosx)+≥2=2,当且仅当sinx+cosx=1时取“=”;∴f(x)的最小值为2.故答案为:2.16.(5分)已知数列{a n}满足na n+2﹣(n+2)a n=λ(n2+2n),其中a1=1,a2=2,若a n<a n+1对∀n∈N*恒成立,则实数λ的取值范围是[0,+∞).﹣(n+2)a n=λ(n2+2n)=λn(n+2),【解答】解:由na n+2得,∴数列{}的奇数项与偶数项均是以λ为公差的等差数列,∵a1=1,a2=2,∴当n为奇数时,,∴;当n为偶数时,,∴.当n为奇数时,由a n<a n+1,得<,即λ(n﹣1)>﹣2.若n=1,λ∈R,若n>1则λ>,∴λ≥0;当n为偶数时,由a n<a n+1,得<,即3nλ>﹣2,∴λ>,即λ≥0.综上,λ的取值范围为[0,+∞).故答案为:[0,+∞).三、解答题(本大题共5小题,共70分.解答应写出文字说明、证明过程或演算步骤.)17.(12分)如图,在△ABC中,点P在BC边上,∠PAC=60°,PC=2,AP+AC=4.(Ⅰ)求∠ACP;(Ⅱ)若△APB的面积是,求sin∠BAP.【解答】(本题满分为12分)解:(Ⅰ)在△APC中,因为∠PAC=60°,PC=2,AP+AC=4,由余弦定理得PC2=AP2+AC2﹣2•AP•AC•cos∠PAC,…(1分)所以22=AP2+(4﹣AP)2﹣2•AP•(4﹣AP)•cos60°,整理得AP2﹣4AP+4=0,…(2分)解得AP=2.…(3分)所以AC=2.…(4分)所以△APC是等边三角形.…(5分)所以∠ACP=60°.…(6分)(Ⅱ)法1:由于∠APB是△APC的外角,所以∠APB=120°.…(7分)因为△APB的面积是,所以.…(8分)所以PB=3.…(9分)在△APB中,AB2=AP2+PB2﹣2•AP•PB•cos∠APB=22+32﹣2×2×3×cos120°=19,所以.…(10分)在△APB中,由正弦定理得,…(11分)所以sin∠BAP==.…(12分)法2:作AD⊥BC,垂足为D,因为△APC是边长为2的等边三角形,所以.…(7分)因为△APB的面积是,所以.…(8分)所以PB=3.…(9分)所以BD=4.在Rt△ADB中,,…(10分)所以,.所以sin∠BAP=sin(∠BAD﹣30°)=sin∠BADcos30°﹣cos∠BADsin30°…(11分)==.…(12分)18.(12分)如图1,在直角梯形ABCD中,AD∥BC,AB⊥BC,BD⊥DC,点E 是BC边的中点,将△ABD沿BD折起,使平面ABD⊥平面BCD,连接AE,AC,DE,得到如图2所示的几何体.(Ⅰ)求证:AB⊥平面ADC;(Ⅱ)若AD=1,二面角C﹣AB﹣D的平面角的正切值为,求二面角B﹣AD ﹣E的余弦值.【解答】解:(Ⅰ)因为平面ABD⊥平面BCD,平面ABD∩平面BCD=BD,又BD⊥DC,所以DC⊥平面ABD.…(1分)因为AB⊂平面ABD,所以DC⊥AB.…(2分)又因为折叠前后均有AD⊥AB,DC∩AD=D,…(3分)所以AB⊥平面ADC.…(4分)(Ⅱ)由(Ⅰ)知AB⊥平面ADC,所以二面角C﹣AB﹣D的平面角为∠CAD.…(5分)又DC⊥平面ABD,AD⊂平面ABD,所以DC⊥AD.依题意.…(6分)因为AD=1,所以.设AB=x(x>0),则.依题意△ABD~△BDC,所以,即.…(7分)解得,故.…(8分)如图所示,建立空间直角坐标系D﹣xyz,则D(0,0,0),,,,,所以,.由(Ⅰ)知平面BAD的法向量.…(9分)设平面ADE的法向量由得令,得,所以.…(10分)所以.…(11分)由图可知二面角B﹣AD﹣E的平面角为锐角,所以二面角B﹣AD﹣E的余弦值为.…(12分)19.(12分)随着移动互联网的快速发展,基于互联网的共享单车应用而生,某市场研究人员为了了解共享单车运营公司M的经营状况,对该公司最近六个月内的市场占有率进行了统计,并绘制了相应的折线图.(Ⅰ)由折线图可以看出,可用线性回归模型拟合月度市场占有率y与月份代码x之间的关系,求y关于x的线性回归方程,并预测M公司2017年4月份(即x=7时)的市场占有率;(Ⅱ)为进一步扩大市场,公司拟再采购一批单车.现有采购成本分别为1000元/辆和1200元/辆的A、B两款车型可供选择,按规定每辆单车最多使用4年,但由于多种原因(如骑行频率等)会导致车辆报废年限不相同.考虑到公司运营的经济效益,该公司决定先对两款车型的单车各100辆进行科学模拟测试,得到两款单车使用寿命频数表如下:1年2年3年4年总计报废年限车型A20353510100B10304020100经测算,平均每辆单车每年可以带来收入500元,不考虑除采购成本之外的其他成本,假设每辆单车的使用寿命都是整数年,且以频率作为每辆单车使用寿命的概率.如果你是M公司的负责人,以每辆单车产生利润的期望值为决策依据,你会选择采购哪款车型?(参考公式:回归直线方程=x +,其中=,=﹣)【解答】解:(Ⅰ)由题意,=3.5,=16,===2,=﹣=16﹣2×3.5=9,∴=2x+9,x=7时,=2×7+9=23,即预测M公司2017年4月份(即x=7时)的市场占有率为23%;(Ⅱ)由频率估计概率,每辆A款车可使用1年,2年,3年、4年的概率分别为0.2,0.35,0.35,0.1,∴每辆A款车的利润数学期望为(500﹣1000)×0.2+(1000﹣1000)×0.35+(1500﹣1000)×0.35+(2000﹣1000)×0.1=175元;每辆B款车可使用1年,2年,3年、4年的概率分别为0.1,0.3,0.4,0.2,∴每辆B款车的利润数学期望为(500﹣1200)×0.1+(1000﹣1200)×0.3+(1500﹣1200)×0.4+(2000﹣1200)×0.2=150元;∵175>150,∴应该采购A款车.20.(12分)如图,点F是抛物线τ:x2=2py (p>0)的焦点,点A是抛物线上的定点,且=(2,0),点B,C是抛物线上的动点,直线AB,AC斜率分别为k1,k2.(I)求抛物线τ的方程;(Ⅱ)若k2﹣k1=2,点D是点B,C处切线的交点,记△BCD的面积为S,证明S 为定值.【解答】解:(Ⅰ)设A(x0,y0),可知F(0,),故.∴,代入x2=2py,得p=2.∴抛物线τ的方程为x2=4y.(Ⅱ)过D作y轴的平行线交BC于点E,并设B(),C(),由(Ⅰ)得A(﹣2,1).=2,∴x2﹣x1=8.直线DBy=,直线CDy=,解得.∴直线BC的方程为y﹣=,将x D代入得.∴△BCD的面积为S=×ED×(x2﹣x1)==(定值)21.(12分)已知函数f(x)=(x3﹣6x2+3x+t)e x,t∈R.(1)若函数y=f(x)有三个不同的极值点,求t的值;(2)若存在实数t∈[0,2],使对任意的x∈[1,m],不等式f(x)≤x恒成立,求正整数m的最大值.【解答】解:(1)f'(x)=(x3﹣3x2﹣9x+3+t)e x,令g(x)=x3﹣3x2﹣9x+3+t,则方程g(x)=0有三个不同的根,又g'(x)=3x2﹣6x﹣9=3(x2﹣2x﹣3)=3(x+1)(x﹣3),令g'(x)=0,得x=﹣1或3,且g(x)在区间(﹣∞,﹣1),(3,+∞)递增,在区间(﹣1,3)递减,故问题等价于即有解得﹣8<t<24.(2)不等式f(x)≤x,即(x3﹣6x2+3x+t)e x≤x,即t≤xe﹣x﹣x3+6x2﹣3x,转化为存在实数t∈[0,2],使对任意的x∈[1,m],不等式t≤xe﹣x﹣x3+6x2﹣3x恒成立,即不等式0≤xe﹣x﹣x3+6x2﹣3x在x∈[1,m]上恒成立,即不等式0≤e﹣x﹣x2+6x﹣3在x∈[1,m]上恒成立.设φ(x)=e﹣x﹣x2+6x﹣3,则φ'(x)=﹣e﹣x﹣2x+6,设r(x)=φ'(x)=﹣e﹣x﹣2x+6,则r'(x)=e﹣x﹣2,因为1≤r≤m,有r'(x)<0,故r(x)在区间[1,m]上是减函数,又r(1)=4﹣e﹣1>0,r(2)=2﹣e﹣2>0,r(3)=﹣e﹣3<0,故存在x0∈(2,3),使得r(x0)=φ'(x0)=0,当1≤x<x0时,有φ'(x)>0,当x>x0时,有φ'(x)<0,从而y=φ(x)在区间[1,x0]上递增,在区间[x0,+∞)上递减.又φ(1)=e﹣1+4>0,φ(2)=e﹣2+5>0,φ(3)=e﹣3+6>0,φ(4)=e﹣4+5>0,φ(5)=e﹣5+2>0,φ(6)=e﹣6﹣3<0,所以当1≤x≤5时,恒有φ(x)>0;当x≥6时,恒有φ'(x)<0.故使命题成立的正整数m的最大值为5.请考生在22、23两题中任选一题作答,如果多做,则按所做的第一题记分.[选修4-4:坐标系与参数方程]22.(10分)在平面直角坐标系xOy中,直线l的参数方程为(t为参数),以坐标原点为极点,x轴的正半轴为极轴建立极坐标系,曲线C的极坐标方程为ρ2=,且直线l经过曲线C的左焦点F.(I )求直线l的普通方程;(Ⅱ)设曲线C的内接矩形的周长为L,求L的最大值.【解答】解:(I)曲线C的极坐标方程为ρ2=,即ρ2+ρ2sin2θ=4,可得直角坐标方程:x2+2y2=4,化为:+=1.∴c==,可得作焦点F.直线l的参数方程为(t为参数),消去参数t可得:x﹣y=m,把代入可得:m=﹣.∴直线l的普通方程为:x﹣y+=0.(II)设椭圆C的内接矩形在第一象限的顶点为.∴椭圆C的内接矩形的周长为L=8cosθ+4sinθ=4sin(θ+φ)≤4(其中tanφ=).∴椭圆C的内接矩形的周长的最大值为4.[选修4-5:不等式选讲]23.已知函数f(x)=|x+1﹣2a|+|x﹣a2|,g(x)=x2﹣2x﹣4+(Ⅰ)若f(2a2﹣1)>4|a﹣1|,求实数a的取值范围;(Ⅱ)若存在实数x,y,使f(x)+g(y)≤0,求实数a的取值范围.【解答】解:(Ⅰ)若f(2a2﹣1)>4|a﹣1|,则|2a2﹣2a|+|a2﹣1|>4|a﹣1|,∴2|a|+|a+1|>4,a<﹣1,则﹣2a﹣a﹣1>4,∴a<﹣,∴a<﹣;﹣1≤a≤0,则﹣2a+a+1>4,∴a<﹣3,不成立;a>0,则2a+a+1>4,∴a>1,综上所述,a<﹣或a>1;(Ⅱ)f(x)=|x+1﹣2a|+|x﹣a2|≥|1﹣2a+a2|,g(x)=x2﹣2x﹣4+=(x ﹣1)2+﹣5≥﹣1若存在实数x,y,使f(x)+g(y)≤0,则|1﹣2a+a2|≤1,∴0≤a≤2.。
洛阳市2020—2021学年高中三年级第一次统一考试数学试卷(理)本试卷分第Ⅰ卷(选择题)和第Ⅱ卷(非选择题)两部分.第Ⅰ卷(选择题)一、选择题: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. 若复数()()112z i i =++,则其共轭复数z 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C根据复数的乘法运算,化简复数z ,从而得出共轭复数z ,再根据复数在复平面上的点的表示,可得选项.∵()()21121+3+21+3i z i i i i =++==-,∴13z i =--,则z 在复平面内对应的点的坐标为(13--,),位于第三象限.故选:C .2. 已知集合{}0A x x =>,{}2230B x x x =+-≤,则集合A B =( )A. {}31x x -≤≤B. {}30x x -≤<C. {}01x x <≤D. {}3x x ≥-D先利用一元二次不等式的解法化简集合B ,再利用并集的运算求解.因为集合{}0A x x =>,{}{}223031B x x x x x =+-≤=-≤≤,所以A B ={}3x x ≥-,故选:D 3. 下列说法正确的是( )A. “()00f =”是“函数()f x 是奇函数”的充要条件B. “若π6α=,则1sin 2α=”的否命题是“若π6α≠,则1sin 2α≠”C. “向量a ,b ,c ,若a b a c ⋅=⋅,则b c =”是真命题D. 命题“x ∀∈R ,2210x x ++>”的否定是“0x ∃∈R ,使得200210x x ++>”B选项A 举例当()2f x x x =-满足()00f =,但不是奇函数,可判断;选项B 写出命题的否命题,可判断;选项C 当0a =时,a b a c ⋅=⋅成立,但b c =不一定成立,可判断,选项D 写出命题的否定,可判断.选项A. 函数()2f x x x =-满足()00f =,但不是奇函数,故A 不正确.选项B. “若π6α=,则1sin 2α=”的否命题是“若π6α≠,则1sin 2α≠”,故B 正确.选项C. 当0a =时,a b a c ⋅=⋅成立,但b c =不一定成立,故C 不正确.选项D. 命题“x ∀∈R ,2210x x ++>”的否定是“0x ∃∈R ,使得200210x x ++≤”,故D 不正确.故选:B4. 在各项均为正数的等比数列{}n a 中,22a =,3564a a =,则数列{}n a 的前10项和等于( ) A. 511 B. 512 C. 1023 D. 1024C由条件求出11,2a q ==,然后可得答案.因为212a a q ==,2635164a a a q ==,且{}n a 的各项为正数所以可解得11,2a q ==,所以101012102312S -==-故选:C 5. 设a 、b 是两条不同的直线,α、β是两个不同的平面,则下列命题中正确的是( ) A. 若a 平行于α内的无数条直线,则//a α B. 若//a α,//a b ,则b 平行于α内的无数条直线 C. 若αβ⊥,a α⊂,b β⊂,则a b ⊥ D. 若//a α,αβ⊥,则a β⊥ B根据空间线面间平行与垂直的位置关系判断. 当a α⊂时,α内也有无数条直线与a 平行,A 错;//a α,则α内有无数条直线与a 平行,而//a b ,那么这无数条直线中最多有一条与b 重合,其它的都与b 平行,B 正确;αβ⊥,a α⊂,b β⊂,a 与b 可能平行可能垂直,C 错;//a α,αβ⊥,则也可能有//a β,D 错误.故选:B .6. 为了得到函数sin 2cos2y x x =+的图像,只需把函数sin 2cos 2y x x =-的图像( )A. 向左平移4π个长度单位B. 向右平移4π个单位长度 C. 向左平移2π个单位长度D. 向右平移2π个单位长度Ay sin2x cos2x =+可化为)4y x π=+,同理y sin2x cos2x =-可化为)4y x π=-,所以把)4y x π=-的图象向左平移4π个单位,可得到)4y x π=+的图像.选A.7. 为创建全国文明城市,学校计划从4男3女共7名教师中随机派出4名教师参加志愿服务工作,则至多有一名女教师参加的概率是( ) A. 1235B.1335C.1835D.1935B由条件可得至多有一名女教师参加的概率为43144347C C C C +,算出即可.至多有一名女教师参加的概率为431443471335C C C C +=故选:B 8. 已知点F 为双曲线22221x y a b -=(0a >,0b >)的左焦点.直线l :y x =-与双曲线的左支交于点P ,且OP PF =(O 为坐标原点),则此双曲线的离心率为( )A.B.C.D. A首先根据条件求出点P 的坐标,然后根据双曲线的定义可建立方程求解.因为OP PF =,直线l :y x =-,所以45PFO POF ∠=∠=︒因为OF c =,所以可得,22c c P ⎛⎫-⎪⎝⎭,22PF = 设双曲线的右焦点为1F ,由双曲线的定义可得12PF PF a -=222222c c c a ⎛⎫⎛⎫--+= ⎪ ⎪⎝⎭⎝⎭10222a -= 所以1022102cae ==-=故选:A 9. 已知P ,Q 是圆O :228x y +=上的两个动点,且4OP OQ -=,S 是线段PQ 的中点,若3122OT OQ OP =-,则OS OT ⋅的值为( )A. 822+B. 822-C. 8D. 4D根据222OP OQ PQ +=,建立平面直角坐标系,分别求得向量,OS OT 的坐标,然后利用平面向量的数量积运算求解.因为P ,Q 是圆O :228x y +=上的两个动点,且4OP OQ -=, 所以222OP OQ PQ +=,建立如图所示直角坐标系:不妨设()(22,0,0,22,2,2P Q S ,所以()2,2OS =,(312,3222OT OQ OP =-=-,所以3122322422OS OQ OT OP =-=-⨯=⋅,故选:D10. 设函数()3211232x b f ax x c x =+++在0,1上取得极大值,在1,2上取得极小值,则3a b+的取值范围是( ) A. ()2,1-- B. ()2,0-C.1,0D. ()1,1-B因为函数()3211232x b f ax x c x =+++在0,1上取得极大值,在1,2上取得极小值, 所以'''(0)20(1)120(2)4220f b f a b f a b ⎧=>⎪=++<⎨⎪=++>⎩,然后画出变量,a b 表示的可行域如图所示,利用线性规划可求得结果由()3211232x b f ax x c x =+++,得'2()2f x x ax b =++,因为函数()3211232x b f ax x c x =+++在0,1上取得极大值,在1,2上取得极小值,所以'''(0)20(1)120(2)4220f b f a b f a b ⎧=>⎪=++<⎨⎪=++>⎩,所以变量,a b 表示的可行域如图所示设3z a b =+,则1133b a z =-+,作直线13b a =-,平移过点(2,0)A -和点C 时,可求得3z a b=+取值范围,由1204220a b a b ++=⎧⎨++=⎩,解得31a b =-⎧⎨=⎩,即(3,1)C -,所以203331z -+⨯<<-+⨯,即20z -<< 所以3a b +的取值范围为()2,0-,故选:B11. 已知1F ,2F 是椭圆2212516x y +=的左、右焦点,P 是椭圆上任意一点,过1F 引12F PF ∠的外角平分线的垂线,垂足为Q ,则Q 与短轴端点的最近距离为( ) A. 1 B. 2 C. 4 D. 5A根据角平分线的性质和椭圆的定义可得OQ 是12F F M △的中位线, ||5OQ a ==,可得Q 点的轨迹是以O 为圆心,以5为半径的圆,由此可得选项.因为P 是焦点为1F ,2F 的椭圆2212516x y +=上的一点,PQ 为12F PF ∠的外角平分线,1QF PQ ⊥,设1F Q 的延长线交2F P 的延长线于点M ,所以1||||PM PF =,12212210,PF PF a MF PF PF +==∴=+,所以由题意得OQ 是12F F M △的中位线,所以||5OQ a ==,所以Q 点的轨迹是以O 为圆心,以5为半径的圆,所以当点Q 与y 轴重合时,Q 与短轴端点取最近距离54 1.d =-=故选:A.12. 已知奇函数()f x 的定义域为ππ,22⎛⎫- ⎪⎝⎭,其图象是一段连续不断的曲线,当π02x -<<时,有()()cos sin 0f x x f x x '+>成立,则关于x 的不等式()π2cos 3f x f x ⎛⎫< ⎪⎝⎭的解集为( )A. ππ23⎛⎫- ⎪⎝⎭,B. ππ23⎛⎫-- ⎪⎝⎭, C. ππππ2332⎛⎫⎛⎫-- ⎪ ⎪⎝⎭⎝⎭,, D. πππ0332⎛⎫⎛⎫- ⎪ ⎪⎝⎭⎝⎭,, A 设()()cos f x g x x=,则()()()2cos sin cos f x x f x xg x x'+'=,由条件可得()()cos f x g x x =在02π⎛⎫- ⎪⎝⎭,上单调递增,进一步可得()()cos f x g x x =在02,上单调递增,将()π2cos 3f x f x ⎛⎫< ⎪⎝⎭可化为()π3πcos cos 3f f x x ⎛⎫⎪⎝⎭<,即()3g x g π⎛⎫< ⎪⎝⎭,由单调性可得答案.设()()cos f x g x x= ,则()()()2cos sin cos f x x f x xg x x'+'=当π02x -<<时,有()()cos sin 0f x x f x x '+>成立,此时()0g x '> 所以()()cos f x g x x =在02π⎛⎫- ⎪⎝⎭,上单调递增. 又()f x 为奇函数,则()00f =,则()()cos f x g x x=为奇函数,又()00g =则()()cos f x g x x =在02,上单调递增,所以()g x 在ππ,22⎛⎫- ⎪⎝⎭上单调递增.当ππ,22x ⎛⎫∈- ⎪⎝⎭,恒有cos 0x >()π2cos 3f x f x ⎛⎫< ⎪⎝⎭可化为()π3πcos cos 3f f x x ⎛⎫ ⎪⎝⎭<,即()3g x g π⎛⎫< ⎪⎝⎭,由()()cos f x g x x =在ππ,22⎛⎫- ⎪⎝⎭上单调递增,所以23x ππ-<<故选:A第Ⅱ卷(非选择题)二、填空题13. 已知向量(),3k =a 与()2,1b =-,若()b a b ⊥+,则实数k 的值为______.1-首先算出a b +的坐标,然后由()b a b ⊥+建立方程求解即可. 因为(),3k =a ,()2,1b =-,所以()2,2a b k +=+ 因为()b a b ⊥+,所以2420k +-=,解得1k =- 故答案为:1-14. 已知π1tan 43α⎛⎫-=- ⎪⎝⎭,则sin cos αα的值是______.25由π1tan 43α⎛⎫-=- ⎪⎝⎭可得cos sin 1cos sin 3αααα-=-+,两边平方可解出答案. 由π1tan 43α⎛⎫-=- ⎪⎝⎭,得sin 11tan cos sin 1cos sin 1tan cos sin 31cos αααααααααα---===-+++ 由cos sin 1cos sin 3αααα-=-+两边平方可得:12cos sin 112cos sin 9αααα-=+ 解得2sin cos 5αα=故答案为:2515. 某几何体的三视图如图所示,则该几何体的体积为______.53根据三视图画出几何体的直观图,再由几何体的构成分别求体积即可.几何体的直观图如下:由三视图得1153+=132+3223V V V=⨯⨯柱锥.故答案为:53【注意点点睛】观察三视图并将其“翻译”成直观图;注意三视图的三要素“高平齐,长对正,宽相等”;注意实线与虚线以及相同图形的不同位置对几何体直观图的影响;对简单组合体三视图问题,先看俯视图确定底面的形状,再根据正视图和侧视图,确定几何体的形状.16. 设数列{}n a满足125a=,且21n n na a a+=+,n*∈N,设122020111111Sa a a=++⋅⋅⋅++++,若(),1S t t∈+,则整数t=______.2先求出+11111n n na a a=-+,再裂项相消得到(2,3)S∈,即得t值.因为21n n n a a a +=+,所以+11111=(1)1n n n n n a a a a a =-++, 所以+11111n n n a a a =-+, 所以122020122320202021111111111111S a a a a a a a a a =++⋅⋅⋅+=-+-++-+++所以202151522S a =-<. 又21n n n a a a +=+,所以1n n a a +>, 由题得223424141414546639366,(),,525252525625390625a a a =+==+==,因为12341111525625390625+++211117391171639366a a a a +=++>++++, 所以(2,3),2S t∈∴=. 故答案为:2三、解答题:解答应写出必要的文字说明、证明过程或演算步骤. 17. 在ABC 中,角A ,B ,C 的对边分别是a ,b ,c ,已知sin sin sin sin b B c C C a A ⎫+=+⎪⎪⎝⎭.(1)求角A ;(2)若D 是AB 的中点,且1CD =,求b c +的最大值.(1)3A π=;(2)3. (1)利用正余弦定理将sin sin sin sin b B c C C a A ⎫+=+⎪⎪⎝⎭进行边角互化可得答案;(2)在ADC 中,设ACD α∠=,ADC β=,则23παβ+=,然后由正弦定理可得sin sin sinAC AD CD A βα===,然后)()222sin 4sin 2sin 4sin 3333b c AC AD πβααα⎡⎤⎛⎫+=+=+=-+ ⎪⎢⎥⎝⎭⎣⎦,利用三角函数的知识可求得答案.(1)因为23sin sin sin sin 3b B c C b C a A ⎛⎫+=+ ⎪ ⎪⎝⎭所以由正弦定理可得2223sin b c b C a a ⎛⎫+=+ ⎪ ⎪⎝⎭,即22223sin 3b c a ab C +-= 所以由余弦定理可得232cos sin bc A ab C =,所以3sin cos sin sin C A A C = 因为sin 0C ≠,所以3cos sin A A =,即tan 3A = 因为()0,A π∈,所以3A π=(2)在ADC 中,设ACD α∠=,ADC β=,则23παβ+=所以23sin sin sin AC AD CD A βα=== 所以)()333222sin 4sin 2sin 4sin 3333b c AC AD πβααα⎡⎤⎛⎫+=+=+=-+ ⎪⎢⎥⎝⎭⎣⎦)()32215sin 333αααϕ==+(其中3tan 5ϕ=) 因为20,3πα⎛⎫∈ ⎪⎝⎭,所以()221221sin 33b c αϕ+=+≤,即b c +22118. 如图,在三棱柱111ABC A B C -中,侧面11AA C C ⊥底面ABC ,160C CA ∠=︒,AB AC ⊥,12AC AB AA ===.(1)求证:11CA BC ⊥;(2)设点E 在直线1AA 上,记1AE AA λ=,是否存在实数λ,使CE 与1A BC 平面所成的角的正25,若存在,求出λ的值;若不存在,请说明理由. (1)证明见解析 (2)存在 1λ=-(1) 连接1AC ,得11AC AC ⊥,由条件可得AB ⊥面11AAC C ,从而有1AB A C ⊥,则可证明1A C ⊥面1ABC ,从而可证明结论.(2) 由(1)可知四边形11AAC C 为菱形,又160C CA ∠=︒,则1CC A △为等边三角形.取AC 的中点N ,连接1C N ,则1C N AC ⊥,且13C N =由侧面11AA C C ⊥底面ABC ,则1C N ⊥面ABC ,以,AC AB 分别为,x y 轴,过A 作1C N 的平行线为z 轴,建立空间直角坐标系,用向量法求解. (1)连接1AC由侧面11AA C C ⊥底面ABC ,且面11AAC C底面ABC AC =,AB AC ⊥, AB 面ABC ,所以AB ⊥面11AAC C又1AC ⊂面11AAC C ,所以1AB A C ⊥ 在三棱柱111ABC A B C -中,侧面11AAC C 为平行四边形,又2AC AB ==, 所以四边形11AAC C 为菱形,则11AC AC ⊥,且1AC AB A =所以1A C ⊥面1ABC ,由1BC ⊂面1ABC ,所以11CA BC ⊥(2)由(1)可知四边形11AAC C 为菱形,又160C CA ∠=︒,则1CC A △为等边三角形. 取AC 的中点N ,连接1C N ,则1C N AC ⊥,且13C N = 由侧面11AA C C ⊥底面ABC ,则1C N ⊥面ABC以,AC AB 分别为,x y 轴,过A 作1C N 的平行线为z 轴,如图建立空间直角坐标系.则()()()()10,0,0,2,0,0,0,2,0,1,0,3A C B A - 由()1,0,3AE AA λλλ==-,则()()()2,0,0,0,32,0,3CE CA AE λλλλ=+=-+-=--()2,2,0BC =-,()11,2,3BA =-- 设面1A BC 的一个法向量为(),,n x y z =则100n BC n BA ⎧⋅=⎪⎨⋅=⎪⎩ ,即220230x y x y z -+=⎧⎪⎨--+=⎪⎩ ,取()1,1,3n = 设CE 与1A BC 平面所成的角为θ,则25sin cos ,n CE n CE n CEθ⋅===⋅ 即()222225552++3λλλ-=⋅,化简得2210λλ++=,所以1λ=- 所以存在1λ=-满足条件.19. 设抛物线C :22y px =(0p >)的焦点为F ,点()4,P m 是抛物线C 上一点,且5PF =. (1)求抛物线C 的方程;(2)设直线l 与抛物线C 交于A ,B 两点,若6AF BF +=,求证:线段AB 的垂直平分线过定点.(1)24y x =;(2)证明见解析. (1)由条件可得542pPF ==+,解出即可; (2)当直线l 的斜率存在时,设:l y kx m =+,()()1122,,,A x y B x y ,联立直线与抛物线的方程联立消元,然后韦达定理可得12242kmx x k-+=,由6AF BF +=可得12242242km x m k kkx -+==⇒=-,然后表示出线段AB 的垂直平分线方程可得答案. (1)由抛物线的焦半径公式可得542pPF ==+,解得2p = 即抛物线C 的方程为24y x =(2)当直线l 的斜率存在时,设:l y kx m =+,()()1122,,,A x y B x y由24y x y kx m ⎧=⎨=+⎩可得()222240k x km x m +-+= 所以0k ≠,()2222440km k m ∆=-->,即1km <12242kmx x k -+=因为6AF BF +=,所以1226x x ++=,所以12242242km x m k k kx -+==⇒=- 所以线段AB 的中点坐标为()2,2k m +所以线段AB 的垂直平分线方程为()122x ky k m ---=-, 即()1214124x k m x x k k k k ky +++=+=--=--,所以过定点()4,0当直线l 的斜率不存在时也满足综上:线段AB 的垂直平分线过定点()4,020. 核酸检测是诊断新冠肺炎的重要依据,首先取病人的唾液或咽拭子的样本,再提取唾液或咽拭子样本里的遗传物质,如果有病毒,样本检测会呈现阳性,否则为阴性.多个样本检测时,既可以逐个化验,也可以将若干个样本混合在一起化验,混合样本中只要有病毒,则混合样本化验结果就会呈阳性,若混合样本呈阳性,则将该组中各个样本再逐个化验;若混合样本呈阴性,则该组各个样本均为阴性.根据统计发现,疑似病例核酸检测呈阳性的概率为p (01p <<).现有4例疑似病例,对其核酸检测有以下三种方案: 方案一:逐个化验;方案二:四个样本混在一起化验; 方案三:平均分成两组化验.(1)若14p =,求2个疑似病例的混合样本化验结果为阳性的概率;(2)在新冠肺炎爆发初期,由于检查能力不足,化检次数的期望值越小,则方案越“优”.若14p =,现将该4例疑似病例样本进行化验.请问:方案一、二中哪个更“优”?(3)若12p =,求方案三检测次数的分布列.(1)716;(2)方案二更“优”;(3)分布列见解析.(1)根据题意直接可得答案;(2)方案二:检测次数为X ,X 的可能取值为1,5,算出其期望,然后与4作比较即可; (3)首先算出每组检测的次数及其概率,然后可得方案三的检测次数为Y ,Y 的可能取值为2,4,6,算出对应的概率,然后可得分布列.(1)该混合样本呈阳性的概率是:2371416⎛⎫-= ⎪⎝⎭;(2)方案一:逐个检测,检测次数为4 方案二:检测次数为X ,X 的可能取值为1,5()()()418117511,5114256256P X P X P X ⎛⎫==-===-==⎪⎝⎭ 所以()811752391525625664E X =⨯+⨯= 由于239464>,所以方案二更“优” (3)方案三,每组两个样本检测时,若呈阴性,则检验次数为1,概率为21124⎛⎫= ⎪⎝⎭若呈阳性,则检验次数为3,概率为13144-= 故方案三的检测次数为Y ,Y 的可能取值为2,4,6()()()2211133392,42,3416448416P Y P Y P Y ⎛⎫⎛⎫=====⨯⨯==== ⎪ ⎪⎝⎭⎝⎭所以随机变量Y分布列为21. 已知函数()()e 1e xf x a x x=+--(1)当0a =时,求函数()f x 的极值;(2)若函数()f x 在区间()0,1内存在零点,求实数a 的取值范围. (1)()f x 的极小值为()10f =,无极大值;(2)()0,∞+.(1)当0a =时,()e e xf x x=-,利用导数求出其单调性即可;(2)()()()()2e 1e=0=e 0xx f x a x g x ax a e x x=+--⇔+-+=,()f x 在区间()0,1上的零点即()g x 在区间()0,1上的零点,然后分0a =、0a >、0a <三种情况讨论,每种情况下结合()g x 的单调性和函数值的符号可得答案.(1)当0a =时,()e e xf x x =-,()f x 的定义域为()(),00,-∞⋃+∞()()2e 1x xf x x-'= 由()0f x '>得1x >,由()0f x '<得1x <且0x ≠所以()f x 在(),0-∞,()0,1上单调递减,在()1,+∞上单调递增 所以()f x 的极小值为()10f =,无极大值(2)当()0,1x ∈时,()()()2e 1e=0e 0xx f x a x ax a e x x=+--⇔+-+=令()()2=e x g x ax a e x +-+,则()f x 在区间()0,1上的零点即()g x 在区间()0,1上的零点()=e 2x g x ax a e '+--令()()=e 2x h x g x ax a e '=+--,则()=e 2xh x a '+①当0a =时,()=e 0xh x '>,()h x 单调递增,即()g x '单调递增又()1=0g ',所以当()0,1x ∈时()0g x '<,()g x 在()0,1上单调递减, 又()1=0g ,()g x 在区间()0,1上没有零点②当0a >时,()0h x '>,故()()h x g x '=在()0,1上单调递增 又()()()()0010,110h g a e h g a ''==--<==>所以存在()00,1x ∈,使得()()000h x g x '== 即当()00,x x ∈时,()0g x '<,()g x 单调递减 当()0,1x x ∈时,()0g x '>,()g x 单调递增又因为()01g =,()1=0g ,所以()g x 在区间()0,1上存在零点③当0a <,()0,1x ∈时,令()x x e ex ϕ=-,则()xx e e ϕ'=-因为在()0,1上,()0x ϕ'<,()x ϕ是减函数,所以()()10xx e ex ϕϕ=->= 所以x e ex >,所以()()()()222=e 0x g x ax a e x ex ax a e x a x x +-+>+-+=->所以()g x 在区间()0,1上没有零点综上:要使函数()f x 在区间()0,1内存在零点,则a 的取值范围是()0,∞+选考题:请考生在第22、23题中任选一题作答.如果多做,则按所做的第一题计分.作答时,用2B 铅笔在答题卡上把所选题目对应的题号后的方框涂黑. 选修4—4:极坐标与参数方程22. 在直角坐标系xOy 中,直线l的参数方程为2x ty ⎧=-⎪⎨=-+⎪⎩(t 为参数),以坐标原点O 为极点,x 轴正半轴为极轴建立极坐标系,曲线C 的极坐标方程为2sin 4cos ρθθ=. (1)求直线l 的普通方程与曲线C 的直角坐标方程; (2)已知点P的直角坐标为),过点P 作直线l 的垂线交曲线C 于D 、E 两点(D 在x 轴上方),求11PD PE-的值. (170y -+=;24y x =;(2(1)利用直线参数方程消去参数即得直线的普通方程,曲线极坐标方程两边同时乘以ρ,利用cos x ρθ=,cos y ρθ=即得曲线的直角坐标方程;(2)根据点P 坐标写直线DE 的参数方程,代入曲线C 的直角坐标方程得关于t 的一元二次方程,利用韦达定理求11PD PE-的值即可.解:(1)由2x ty ⎧=-⎪⎨=-+⎪⎩,消去参数t70y -+=,即直线l70y -+=; 由2sin 4cos ρθθ=得22sin 4cos ρθρθ=, ∵cos x ρθ=,cos y ρθ=,∴24y x =, 即曲线C 的直角坐标方程24y x =;(2)依题意,设直线DE的参数方程为212x t y t ⎧=⎪⎪⎨⎪=⎪⎩(t 为参数), 代入24y x =得20t +-=,设点D 对应的参数为1t ,点E 对应的参数为2t,则12t t +=-12t t =-,且D 在x 轴上方,有10t >,20t <.故121212*********t t PD PE t t t t t t +-=-=+===, 即11PD PE -的值为4. 选修4—5:不等式选讲23. (1)已知a 、b 、c 是正数,且满足1ab bc ac ++=,求证a b c ++≥ (2)已知a 、b 是正数,且满足1a b +=2. (1)证明见解析;(2)证明见解析.(1)本题可通过基本不等式得出222a b c ab bc ac ++≥++,进而得出()()23a b c ab bc ac ++≥++,最后根据1ab bc ac ++=即可证得不等式成立;(2)本题可通过柯西不等式证得不等式成立(1)因为222a b ab +≥,222b c bc +≥,222a c ac +≥,所以()2222222a b c ab bc ac ++≥++,当且仅当a b c ==时取等号,则222a b c ab bc ac ++≥++,()()23a b c ab bc ac ++≥++,因为1ab bc ac ++=,所以()23a b c ++≥,a b c ++≥. (2)因为1a b +=,所以由柯西不等式得()2111122a b ⎡⎤⎛⎫⎛⎫≤++++ ⎪ ⎪⎢⎥⎝⎭⎝⎭⎣⎦ ()214a b =++=(当且仅当12a b ==时取等号),2.。
百度文库精品文档洛阳市2019--2020学年高中三年级第一次统一考试数学试卷(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.已知集合(){}20|M x x x =-<,{}2,1,0,1,2N =--,则M N =( )A. {}0,1B. {}2,1--C. {}1D. {}0,1,2【答案】C 【解析】 【分析】解一元二次不等式求得集合M ,由此求得两个集合的交集. 【详解】由()20x x -<,解得{}|02M x x =<<,所以M N ={}1.故选:C【点睛】本小题主要考查一元二次不等式的解法,考查集合交集的概念和运算,属于基础题. 2.已知复数z 在复平面中对应的点(),x y 满足()2211x y -+=,则1z -=( )A. 0B. 1C.D. 2【答案】B 【解析】 【分析】根据复数对应点的坐标以及复数模的几何意义,判断出正确选项.【详解】由于复数z 在复平面中对应的点(),x y 满足()2211x y -+=,即复数z 对应点在圆心为()1,0,半径为1的圆上,1z -表示复数对应的点到()1,0的距离,也即圆上的点到圆心的距离,所以11z -=. 故选:B【点睛】本小题主要考查复数对应点的坐标以及复数模的几何意义,考查圆的方程,属于基础题. 3.为了节能减排,发展低碳经济,我国政府从2001年起就通过相关政策推动新能源汽车产业发展.下面的图表反映了该产业发展的相关信息:百度文库精品文档根据上述图表信息,下列结论错误的是( )A. 2017年3月份我国新能源汽车的产量不超过3.4万辆B. 2017年我国新能源汽车总销量超过70万辆C. 2018年8月份我国新能源汽车的销量高于产量D. 2019年1月份我国插电式混合动力汽车的销量低于2万辆 【答案】D 【解析】 【分析】根据图表对选项逐一分析,由此确定结论错误的选项. 【详解】对于A 选项,2017年3月份我国新能源汽车的产量 6.8 6.83.32 3.41 1.05 2.05=≈<+,故A 选项结论正确.对于B 选项,2017年我国新能源汽车总销量125.6125.677.677010.617 1.617=≈>+,故B 选项结论正确.对于C 选项,2018年8月份我国新能源汽车的销量10.1万量,高于产量9.9万量,故C 选项结论正确. 对于D 选项,2019年1月份我国插电式混合动力汽车的销量9.60.25 2.42⨯=>,故D 选项结论错误. 故选:D【点睛】本小题主要考查图表数据分析,考查阅读与理解能力,属于基础题.4.已知正项等比数列{}n a 中,354a a =,且467,1,a a a +成等差数列,则该数列公比q 为( ) A.14B.12C. 2D. 4【答案】C 【解析】【分析】结合等差中项的性质,将已知条件转化为1,a q 的形式,由此求得q 的值. 【详解】由于467,1,a a a +成等差数列,所以()64721a a a +=+,所以()64735214a a a a a ⎧+=+⎨=⎩,即()5361112411214a q a q a q a q a q ⎧+=+⎪⎨⋅=⎪⎩,解得11,24a q ==. 故选:C【点睛】本小题主要考查等比数列基本量的计算,考查等差中项的性质,属于基础题.5.我国数学家陈最润在哥德巴赫猜想的研究中取得了世界瞩目的成就.哥德巴赫猜想简述为“每个大于2的偶数可以表示为两个素数的和”(注:如果一个大于1的整数除了1和自身外无其他正因数,则称这个整数为素数),如40337=+.在不超过40的素数,随机选取2个不同的数,这两个数的和等于40的概率是( ) A.126B.122C.117D.115【答案】B 【解析】 【分析】先求得40以内的素数的个数,然后根据古典概型概率计算公式,计算出所求的概率.【详解】40以内的素数为2,3,5,7,11,13,17,19,23,29,31,37共12个,任选两个的方法数有21212116621C ⨯==⨯种,和为40的有33740,112940,172340+=+=+=共3种,所以不超过40的素数,随机选取2个不同的数,这两个数的和等于40的概率是316622=. 故选:B【点睛】选本小题主要考查古典概型的计算,考查组合数的计算,考查素数的知识,属于基础题. 6.圆22 2410x y x y +-++=关于直线()300,0ax by a b --=>>对称,则12a b+的最小值是( ) A. 1 B. 3C. 5D. 9【答案】B 【解析】 【分析】求得圆心,代入直线30ax by --=,利用基本不等式求得12a b+的最小值.【详解】圆222410x y x y +-++=的圆心为()1,2-,由于圆关于直线30ax by --=对称,圆心坐标满足直线方程,所以23a b +=,所以12a b +()1122123253b a a b b b a a +⎛⎫⎛⎫=⋅⋅+=++ ⎪ ⎪⎝⎭⎝⎭()12215254333b a a b ⎛⎫≥+⋅=+= ⎪ ⎪⎝⎭,当且仅当22,1b a a b a b===时等号成立. 故选:B【点睛】本小题主要考查圆的几何性质,考查基本不等式求最小值. 7.函数()()23xx e e cos x f x x-⋅-=(e为自然对数的底数)的大致图象为( )A. B.C. D.【答案】C 【解析】 【分析】根据函数的奇偶性和特殊值,排除错误选项,由此得出正确选项.【详解】由于()()f x f x -=-,所以()f x 为奇函数,图像关于原点对称,由此排除B,D 两个选项. 当0,6x π⎛⎫∈ ⎪⎝⎭时()0f x >,由此排除A 选项. 故选:C【点睛】本小题主要考查函数图像的识别,考查函数的奇偶性,属于基础题. 8.正三棱锥的三视图如下图所示,则该正三棱锥的表面积为( )A. 33033+B. 3309+C. 123D.991022+ 【答案】A 【解析】 【分析】通过三视图还原出立体图,通过条件可求得底面正三角形边长为23,则底面积为33,侧棱长为13,则可求侧面积为330,所以可得表面积.【详解】如图所示,底面正三角的高AD=3,所以223AH AD ==,AB=AC=BC=333ABCS =又SH为侧视图中的高,所以SH=3,则22223213AS AH SH +=+则在等腰SAB 中12310302SABS=⨯=所以侧面积为3033033+A . 【点睛】本题考查已知三视图求几何体的表面积,准确的还原出立体图是解题的关键,属中档题.9.已知点12,F F 分别是双曲线()2222:10,0x yC a b a b-=>>的左,右焦点,O 为坐标原点,点P 在双曲线C 的右支上,且满足1221 2,4F F OP tan PF F =∠=,则双曲线C 的离心率为( ) 5 B. 517D.179【答案】C【解析】 【分析】根据12 2F F OP =判断出三角形12F F P 是直角三角形,利用214tan PF F ∠=、双曲线的定义和勾股定理列方程组,化简后求得离心率.【详解】由于12 22F F OP c ==,所以三角形12F F P 是直角三角形.所以12121222221212424PF tan PF F PF PF PF a PF PF F F c ⎧∠==⎪⎪⎪-=⎨⎪+==⎪⎪⎩,化简得22179c a =,即3c e a ==. 故选:C【点睛】本小题主要考查双曲线离心率的求法,考查双曲线的定义,考查化归与转化的数学思想方法,属于中档题.10.设()f x 是定义在R 上的函数,满足条件()()11f x f x +=-+,且当1x ≤时,()3xf x e-=-,则()27a f log =,()2 1.533,3b f c f --⎛⎫⎪⎝⎭==的大小关系是( )A. a b c >>B. a c b >>C. b a c >>D. c b a >>【答案】B 【解析】 【分析】利用已知条件将()27a f log =转换为247a f log ⎛=⎫⎪⎝⎭,根据1x ≤时()f x 的单调性,比较出,,a b c 的大小关系. 【详解】依题意()()11f x f x +=-+,所以()22277log 1log 1227a f log f f ⎛⎫⎛⎫=+=-+ ⎪ ⎝⎭⎝=⎪⎭24log 7f ⎛⎫= ⎪⎝⎭.因为21.5324log 03317--<<<<,且当(],1x ∈-∞时,()3x f x e -=-为减函数,所以a c b >>.故选:B【点睛】本小题主要考查利用函数的单调性比较大小,考查对数运算,考查化归与转化的数学思想方法,属于基础题.11.正方体1111ABCD A B C D -的棱长为1,点E 为棱1CC 的中点.下列结论:①线段BD 上存在点F ,使得//CF 平面1AD E ;②线段BD 上存在点F ,使CF ⊥得平面1AD E ;③平面1AD E 把正方体分成两部分,较小部分的体积为724,其中所有正确的序号是( ) A. ① B. ③C. ①③D. ①②③【答案】C 【解析】 【分析】利用线面平行的判定定理,作出F 点的位置,判断①正确.利用面面垂直的判定定理,判断②错误.计算较小部分的体积,判断③正确.【详解】设1A D 交1AD 于P ,过P 作PQ AD ⊥,交AD于Q ,连接CQ 交BD 于F ,由于//,PQ CE PQ CE =,所以四边形PQCE 为平行四边形,所以//CQ EP ,所以//CQ 平面1AED .故线段BD 上存在点F ,使得//CF 平面1AD E ,即①正确.若CF ⊥平面1AD E ,CF ⊂平面ABCD ,则平面1AD E ⊥平面ABCD ,这不成立,所以②错误. 延展平面1AD E 为1AMED 如图所示,其中M 是BC 的中点.根据正方体的几何性质可知,1,,D E AM DC 相交于一点, 1CEMDD A ∆∆,所以多面体1CEM DD A -是棱台.且体积为(113CEM DD A S S CD ∆∆⋅+⋅1117138224⎛=⋅++⋅= ⎝.故③正确. 综上所述,正确的序号为①③. 故选:C【点睛】本小题主要考查空间线面平行、线面垂直有关定理,考查台体体积计算,考查空间想象能力和逻辑推理能力,属于中档题.12.已知正项数列{}n a 的前n 项和为1,1n S a >,且2632n n n S a a =++.若对于任意实数[]2,2a ∈-.不等式2*1()211n a t at n N n +<+-∈+恒成立,则实数t 的取值范围为( ) A. ][(),22,⋃∞-+∞- B. ,21,(][)∞⋃+∞--C. ,12[),(]-∞⋃+∞-D. []22-,【答案】A 【解析】 【分析】 求得11n a n ++的范围,转化主参变量列不等式组,解不等式组求得t 的取值范围. 【详解】由2632n n n S a a =++①.当1n =时,2111632a a a =++,解得12a =.当2n ≥时,2111632n n n S a a ---=++②,①-②得2211633n n n n n a a a a a --=-+-,()()1130n n n n a a a a --+--=,所以13n n a a --=,所以数列{}n a 是首项为12a =,公差为3d =的等差数列,所以31n a n =-,所以()1311133111n n a n n n ++-==-<+++,所以2213t at +-≥恒成立,即2240t at +-≥,转换为2240ta t +-≥,在[]2,2a ∈-恒成立,所以2222402240t t t t ⎧-+-≥⎨+-≥⎩,解得][,2()2,t ∈⋃∞-+∞-. 故选:A【点睛】本小题主要考查已知n S 求n a ,考查不等式恒成立问题的求解策略,考查化归与转化的数学思想方法,属于中档题.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.平面向量a 与b 的夹角为60,且()3,0a =,1b =,则2a b += __________.【解析】 【分析】 利用()222a b a b+=+来求得2a b +.【详解】依题意()222a b a b+=+224494a a b b =+⋅+=+=【点睛】本小题主要考查平面向量模的运算,考查平面向量数量积的运算,考查化归与转化的数学思想方法,属于基础题.14.若实数,x y 满足约束条件,4, 3,y x x y y ≤⎧⎪+≤⎨⎪≥-⎩,则2z x y =+的最小值是__________.【答案】9- 【解析】 分析】画出可行域,平移基准直线20x y +=到可行域边界位置,由此求得z 的最小值.【详解】画出可行域如下图所示,平移基准直线20x y +=到可行域边界点()3,3A --位置,此时z 取得最小值为()2339⨯--=-. 故答案:9-【点睛】本小题主要考查线性规划求最小值,考查数形结合的数学思想方法,属于基础题.15.已知椭圆()2222:10,x y C a b A a b+=>>为右顶点.过坐标原点O 的直线交椭圆C 于,P Q 两点,线段AP的中点为M ,直线QM 交x 轴于()2,0N ,椭圆C 的离心率为23,则椭圆C 的标准方程为__________. 【答案】2213620x y += 【解析】 【分析】设出,P Q 两点的坐标,求得M 点坐标,由,,Q M N 三点共线列方程,结合椭圆的离心率求得,a b 的值,进而求得椭圆的标准方程.【详解】设()()0000,,,P x y Q x y --,(),0A a ,所以00,22a x y M +⎛⎫⎪⎝⎭,由于,,Q M N 三点共线,所以0002222y y a x x =++-,解得6a =.由于椭圆离心率23c a =,所以4c =,所以22220,b a c b =-==所以椭圆方程为2213620x y +=. 故答案为:2213620x y += 【点睛】本小题主要考查根据椭圆的离心率求椭圆标准方程,考查运算求解能力,属于基础题. 16.已知函数()()12,f lnx ax a x g x x=+=-,且()()0f x g x ≤在定义域内恒成立,则实数a 的取值范围为__________.【答案】{2|a a e =或12a e ⎫≤-⎬⎭【解析】 【分析】先求得()()f x g x 的定义域,然后对()f x 和()g x 的符合进行分类讨论,由此求得实数a 的取值范围.【详解】依题意()()()1ln 2f x g x x ax a x ⎛⎫=+- ⎪⎝⎭,定义域为()0,∞+.由于()()0f x g x ≤在定义域内恒成立,则①,1ln 20,0x ax a x +≤-≥恒成立,即ln 12,x a a x x ≤-≤在()0,∞+恒成立.令()ln xh x x=-,()'ln 1x h x x -=,故()h x 在()0,e 上递减,在(),e +∞上递增,故()()1h x h e e ≥=-.所以,由ln 12,x a a x x ≤-≤可得12,0a a e ≤-≤,即12a e≤-.②,1ln 20,0x ax a x +≥-≤恒成立,即ln 12,x a a x x≥-≥在()0,∞+恒成立,不存在这样的a . ③,当0a >时,由于()f x 在()0,∞+上递增,()g x 在()0,∞+上递减,要使()()0f x g x ≤在定义域内恒成立,则需()f x 和()g x 有相同的零点.由ln 2010x ax a x+=⎧⎪⎨-=⎪⎩,解得22,a e x e -==.综上所述,实数a 的取值范围是{2|a a e =或12a e ⎫≤-⎬⎭.故答案为:{2|a a e =或12a e ⎫≤-⎬⎭【点睛】本小题主要考查不等式恒成立问题的求解策略,考查利用导数研究函数的单调性和最值,考查分类讨论的数学思想方法,考查化归与转化的数学思想方法,属于难题.三、解答题 (本大题共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.在ABC 中,角,,A B C 对应边分别为,,a b c .(1)若ABC 的面积S 满足222,4c a b c a +=+==且b c >,求b 的值;(2)若3a A π==且ABC 为锐角三角形.求ABC 周长的范围.【答案】(1)b =(2)3(+ 【解析】 【分析】(1)结合三角形面积公式和余弦定理,求得tan C 的值,由此求得C 的大小,利用余弦定理列方程求得b 的值.(2)利用正弦定理表示出,b c ,用三角形内角和定理和三角恒等变换求得b c +的取值范围,由此求得a b c ++即三角形ABC 周长的取值范围.【详解】(1)由条件和三角形的面积公式得2222c c a b +=+=+,即222a b c =+-. 将余弦定理2222a b c abcosC +-=.cosC =,即3tanC =,因为(0,)C π∈,所以6C π=将4,6c a C π===,代入2222c a b abcosC =+-,得290b -+=结合条件b c >得b =(2)由正弦定理得2sin sin sin a b cA B C=== 所以()2b c sinB sinC +=+()22233sinB sin B sinB sin B πππ⎡⎡⎤⎛⎫=--+- ⎪⎢⎥⎝⎭⎣⎤=⎢⎥⎣⎦⎦+3322(36)2sinB cosB sin B π⎛⎫ ⎪ ⎪⎭==+⎝+ 因为A B C π++=,且3A π=及锐角三角形得0,2B π⎛⎫∈ ⎪⎝⎭且20,32B ππ⎛⎫⎛⎫-∈⎪ ⎪⎝⎭⎝⎭, 所以62B ππ<<,所以2363B πππ<+<,即3sin 16B π⎛⎫<+≤ ⎪⎝⎭,所以(3,23]b c +∈ 所以周长a b c ++范围是3 3 (],33+.【点睛】本小题主要考查正弦定理、余弦定理解三角形,考查三角形的面积公式,考查三角恒等变换,考查运算求解能力,属于中档题.18.如图,已知四边形ABCD 为等腰梯形,BDEF 为正方形,平面BDEF ⊥平面ABCD ,//,1AD BC AD AB ==,60ABC ∠=︒.(1)求证:平面CDE ⊥平面BDEF ;(2)点M 为线段EF 上一动点,求BD 与平面BCM 所成角正弦值的取值范围. 【答案】(1)证明见解析(2)51,52⎤⎥⎣⎦ 【解析】 分析】(1)利用等腰梯形的性质证得BD CD ⊥,由面面垂直的性质定理证得CD ⊥平面BDEF ,由此证得平面CDE ⊥平面BDEF .(2)建立空间直角坐标系,设出EM 的长,利用直线BD 的方向向量和平面BCM 的法向量,求得BD 与平面BCM 所成角正弦值的表达式,进而求得BD 与平面BCM 所成角正弦值的取值范围. 【详解】在等腰梯形ABCD 中,// ,1AD BC AD AB ==, 60ABC ∠=︒,120,30BAD CDA ADB ∴∠=∠=︒∠=︒,90CDB ∠=︒. 即.BD CD ⊥2221203BD AB AD AB AD cos =+-⋅⋅︒=,2BC =.又平面BDEF ⊥平面ABCD ,平面BDEF ⋂平面,ABCD BD CD =⊂平面ABCD ,∴CD ⊥平面BDEFCD ⊂平面CDE ,∴平面CDE ⊥平面BDEF(2)解:由(1)知,分别以直线,,DB DC DE 为x 轴,y 轴,z 轴建立空间直角坐标系, 设03()EM m m =≤≤,则()()3,0,0,0,1,0,000),(,B C D ,(()3,3,1,0M m BC =-,()3,0,3,3,0,()0BM m DB =-=设平面BMC 的法向量为(),,n x y x =00n BC n BM ⎧⋅=∴⎨⋅=⎩,即(130330x y m x z ⎧+=⎪⎨-+=⎪⎩令3x =,则3,3y z m ==,平面BMC 的一个法向量为3,3,3()n m =. 设BD 与平面BCM 所成角为θ,,sin cos n BD θ∴=<>(,nBD n BDm ==∴当0m =m 时取最大值12故BD 与平面BCM 所成角正弦值的取值范围为1,52⎤⎥⎣⎦. 【点睛】本小题主要考查面面垂直的判定定理和性质定理,考查向量法计算线面角正弦值的取值范围,考查空间想象能力和逻辑推理能力,属于中档题.19.过点()0,2P 的直线与抛物线2:4C x y =相交于,A B 两点. (1)若2AP PB =,且点A 在第一象限,求直线AB 的方程;(2)若,A B 在直线2y =-上的射影分别为11,A B ,线段11A B 的中点为Q , 求证1//BQ PA . 【答案】(1)240x y -+=.(2)证明见解析 【解析】 【分析】(1)设出直线AB 的方程,联立直线AB 的方程和抛物线方程,化简后写出韦达定理,利用2AP PB =,结合平面向量相等的坐标运算、韦达定理,求得直线AB 的斜率,进而求得直线AB 的方程. (2)由(1)求得11,,A B Q 的坐标,通过计算10BQ PA k k -=,证得1//BQ PA . 【详解】(1)设AB 方程为()20y kx k =+>,()()11221,,,,0A x y B x y x > ,联立方程24 2.x y y kx ⎧=⎨=+⎩,,消去y 得:2480x kx --=,216320k =+>,121248x x kx x +=⎧⎨⋅=-⎩①又()1122(),2,,2AP x y PB x y =--=- 由2AP PB =得:122x x =- 代人①解得12k =∴直线AB 的方程为:122y x =+,即240x y -+=. (2)由(1)得,()111122,2,,2(()2),,2x A x B x Q x +---114PA k x =-, ()22221221228422BQx x k x x x x x ++==+-- ()()()122121212211121888422BQ PA x x x x x x k k x x x x x x ++-+-=+=-- ()()()221212212112188022x x x x x x x x x x x x ++===-- 1BQ PA k k ∴=1//PA BQ ∴【点睛】本小题主要考查直线和抛物线的位置关系,考查向量的坐标运算,考查化归与转化的数学思想方法,考查运算求解能力,属于中档题. 20.设函数()()3211232xf x ex kx kx =--+. (1)若1k =,求()f x 的单调区间;(2)若()f x 存在三个极值点123,,x x x ,且123x x x <<,求k 的取值范围,并证明:1 3 22x x x >+. 【答案】(1)单调减区间为(,1)-∞,单调增区间为(1,)+∞.(2)k e >,证明见解析 【解析】 【分析】(1)当1k =时,利用导数求得()f x 的单调区间. (2)先求得()f x 的导函数()()()'1x e x fx kx --=,则()x g x e kx =-有两个不同的零点,且都不是1.对k分成0,0k k ≤>两种情况分类讨论,利用导数研究()g x 的单调性和零点,由此求得k 的取值范围. 由上述分析可得12301x x x <<=<,利用导数证得312313131ln ln 221x x x x x x x x x -=>=-++,从而证得1 3 22x x x >+.【详解】(1)()32()11232xf x e x x x =--+ ()()() 1x f x e x x '∴=--.百度文库精品文档令()(),'1xxh x e x h x e =-=-,()'0h x >得0x >,()'0h x <得0x <, ()h x 在(,0)-∞上递减,在(0,)+∞上递增.()()010h x h ∴≥=>即0x e x ->,∴解()'0f x >得1x >,解()'0f x <得1x <,()f x ∴的单调减区间为(,1)-∞,单调增区间为(1,)+∞.(2)()()()()2'21xx x f x ex e kx kx e kx x =-+-+=--,()f x 有三个极值点,∴方程0-=x e kx 有两个不等根,且都不是1,令()xg x e kx =-,0k ≤时,()g x 单调递增,()0g x =至多有一根,0k ∴>解()'0g x >得x lnk >,解()'0g x <得x lnk <. ()g x ∴在(n ),l k -∞上递减,在(ln ,)k +∞上递增,()()ln 10,k g lnk e klnk k lnk k e =-=-<>∴此时,()010g =>,()1,10lnk g e k >=-<,x →+∞时()g x →+∞.k e ∴>时,()'0f x =有三个根123,,x x x ,且12301x x x <<=<,由11xe kx =得11x lnk lnx =+,由33x e kx =得33x lnk lnx =+,3131ln ln 1x x x x -∴=-下面证明:313131ln ln 2x x x x x x ->-+,可变形为331311121x x xln x x x ->+令311x t x =>,()()21ln 1t x t t ϕ-=-+ ()()()()222114011t x t t t t ϕ-'=-=>++,()x ϕ∴在(1)+∞,上递增, ()()10t ϕϕ∴>=∴313131ln ln 21x x x x x x -=>-+,3122.x x x ∴+>【点睛】本小题主要考查利用导数研究函数的单调性,考查利用导数求解函数极值有关问题,考查利用导数证明不等式,考查化归与转化的数学思想方法,考查运算求解能力,属于难题.21.“公平正义”是社会主义和谐社会的重要特征,是社会主义法治理念的价值追求.“考试”作为一种公平公正选拔人才的有效途径,正被广泛采用.每次考试过后,考生最关心的问题是:自己的考试名次是多少?自已能否被录取?能获得什么样的职位? 某单位准备通过考试(按照高分优先录取的原则)录用300名,其中275个高薪职位和25个普薪职位.实际报名人数为2000名,考试满分为400分.(一般地,对于一次成功的考试来说,考试成绩应服从正态分布. )考试后考试成绩的部分统计结果如下: 考试平均成绩是180分,360分及其以上的高分考生30名. (1)最低录取分数是多少?(结果保留为整数)(2)考生甲的成绩为286分,若甲被录取,能否获得高薪职位?若不能被录取,请说明理由. 参考资料:(1)当2~(,)X N μσ时,令X Y μσ-=,则()~0,1Y N .(2)当()~0,1Y N 时, 2.17()0.985P Y ≤≈, 1.280.900, 1.()09()0.863P Y P Y ≤≈≤≈,1.04()0.85P Y ≤≈.【答案】(1)266分或267分.(2)能获得高薪职位.见解析 【解析】 【分析】(1)利用考试的平均成绩、高分考生的人数,以及题目所给正态分布的参考资料,求得考生成绩X 的分布()~180,832X N ,利用录取率3002000列方程,由此求得最低录取分数线. (2)计算出不低于考生甲的成绩的人数约为200,由此判断出甲能获得高薪职位. 【详解】(1)设考生成绩为X ,则依题意X 应服从正态分布,即()2~180,X N σ.令180X Y σ-=,则()~0,1Y N .由360分及其以上的高分考生30名可得()303602000P X ≥= 即()3036010.9852000P X <=-≈,亦即3601800.985P Y σ-⎛⎫<≈ ⎪⎝⎭.则3601802.17σ-=,解得()83180,832N σ≈∴,, 设最低录取分数线为o x ,则0180300832(0)00o x P X x P Y -⎛⎫≥=≥=⎪⎝⎭ 则018030010.85832000x P Y -⎛⎫<=-≈ ⎪⎝⎭,01801.0483x -∴= 266.32o x ∴≈.即最低录取分数线为266分或267分. (2)考生甲的成绩286267>,所以能被录取.()()286180()286 1.280.9083P X P Y P Y -<=<=<≈, 表明不低于考生甲的成绩的人数约为总人数的10.900.10,20000.1200-=⨯≈, 即考生甲大约排在第200名,排在275名之前,所以他能获得高薪职位.【点睛】本小题主要考查正态分布在实际生活中的应用,考查化归与转化的数学思想方法,考查阅读理解能力,属于中档题.请考生在第22、23题中任选一题做答,如果多做,则按所做的第一题记分.做答时,用2B 铅笔在答题卡.上把所选题目对应的题号后的方框涂黑.22.在极坐标系中,已知圆的圆心6,3C π⎛⎫⎪⎝⎭,半径3r =,Q 点在圆C 上运动.以极点为直角坐标系原点,极轴为x 轴正半轴建立直角坐标系. (1)求圆C 的参数方程;(2)若P 点在线段OQ 上,且:2:3OP PQ =,求动点P 轨迹的极坐标方程.【答案】(1)33cos 3sin x y θθ=+⎧⎪⎨=⎪⎩(θ为参数);(2)225120sin 10806πρρθ⎛⎫-++= ⎪⎝⎭【解析】【分析】(1)已知得,圆心6,3C π⎛⎫ ⎪⎝⎭的直角坐标为(C ,3r =,则可求得圆的标准方程;(2)结合(1)得,圆C 的极坐标方程为212sin 276πρρθ⎛⎫=+- ⎪⎝⎭,再设(),P ρθ,()1,Q ρθ,则1:2:5ρρ=,将152ρρ=代入C 的极坐标方程即可得解. 【详解】(1)由已知得,圆心6,3C π⎛⎫ ⎪⎝⎭的直角坐标为(C ,3r =, 所以C 的直角坐标方程为()(2239x y -+-=,所以圆C的参数方程为33cos 3sin x y θθ=+⎧⎪⎨=⎪⎩(θ为参数). (2)由(1)得,圆C的极坐标方程为()26cos 270ρρθθ-+=, 即212sin 276πρρθ⎛⎫=+- ⎪⎝⎭. 设(),P ρθ,()1,Q ρθ,根据:2:3OP PQ =,可得1:2:5ρρ=, 将152ρρ=代入C 的极坐标方程,得225120sin 10806πρρθ⎛⎫-++= ⎪⎝⎭, 即动点p 轨迹的极坐标方程为225120sin 10806πρρθ⎛⎫-++= ⎪⎝⎭. 【点睛】本题考查了直角坐标方程、极坐标方程及参数方程的互化,重点考查了运算能力,属基础题. 23.设函数()211f x x x =-++.(1)画出()y f x =的图象;(2)若不等式()1f x a x >-+对x ∈R成立,求实数a 的取值范围.【答案】(1)见解析(2)(,3)-∞【解析】【分析】(1)利用零点分段法将()f x 表示为分段函数的形式,由此画出()f x 的图形.(2)将不等式() 1f x a x >-+转化为21 22a x x -++>.利用绝对值不等式求得21 22x x -++的最小值,由此求得a 的取值范围.【详解】(1)根据绝对值的定义,可得()3,112,1213,2x x f x x x x x ⎧⎪-<-⎪⎪=-+-≤≤⎨⎪⎪>⎪⎩所以() y f x =的图象如图所示:(2)() 1f x a x >-+,即21 22a x x -++>|21 2 2 2122|3x x x x -++≥---=,3a ∴<,即实数a 的取值范围是(,3)-∞.【点睛】本小题主要考查分段函数的图像,考查含有绝对值的不等式恒成立问题的求解,属于基础题.百度文库精品文档1、想想自己一路走来的心路历程,真的很颓废一事无成。
2020-2021学年河南省洛阳市高三(上)第一次统考化学试卷一、选择题(本题共10小题,每小题只有一个选项符合题意,每小题2分,共20分)1.化学与生活生产密切相关。
下列说法正确的是()A.石墨烯是一种能导电的有机高分子材料B.汉代烧制出“明如镜、声如磬”的瓷器,其主要原料为黏土C.泡沫灭火器可用于一般的灭火,也适用于电器灭火D.“绿色化学”的核心是应用化学原理对环境污染进行治理2.下列关于物质的保存不正确的是()A.漂白粉可露置于空气中保存B.金属钠应用煤油液封C.液溴应用水封存D.次氯酸应保存在棕色瓶中3.用化学用语表示2Na+2H2O═2NaOH+H2↑中的相关微粒,其中正确的是()A.中子数为10的氧原子:OB.NaOH的电子式:C.Na+的结构示意图:D.H2O的比例模型:4.下列说法正确的是()A.冠状病毒粒子直径约60~220nm,故介于溶液和胶体粒子之间B.装有无水硫酸铜的透气袋可以用作食品干燥剂C.二氧化硅可用做计算机芯片D.免洗手消毒液的成分活性银离子、乙醇均能使蛋白质变性5.分类是学习和研究化学的一种常用的科学方法,下列分类合理的是()①根据酸分子中含有H原子个数将酸分为一元酸、二元酸等②碱性氧化物一定是金属氧化物③根椐丁达尔现象可将分散系分为胶体、溶液和浊液④SiO2能与NaOH溶液反应生成Na2SiO3和水,SiO2是酸性氧化物。
A.②③B.②④C.①②④D.②③④6.常温下,下列各组离子在指定的溶液中一定能大量共存的是()A.1mol•L﹣1NaClO溶液:H+、SO42﹣、I﹣、Na+B.使酚酞呈红色的溶液中:K+、Na+、NO3﹣、Cl﹣C.无色透明的溶液中:K+、NH4+、MnO4﹣、CO32﹣D.由水电离的c(OH﹣)=1×10﹣14mol•L﹣1的溶液:K+、Cl﹣、HCO3﹣、Na+7.设N A为阿伏加德罗常数的值,下列说法正确的是()A.2mol•L﹣1的AlCl3溶液中含有Al3+的数目小于2N AB.常温常压下,2.2g CO2和N2O的混合气体含有的原子数为0.15N AC.300mL 2mol•L﹣1蔗糖溶液中所含分子数为0.6N AD.在密闭容器中通入2mol SO2和1mol O2,一定条件下充分反应生成SO3的分子数为2N A 8.下列制取SO2、验证其性质的装置(尾气处理装置已省略)和原理不能达到实验目的是()A.制取SO2B.验证漂白性C.验证还原性D.验证氧化性9.下列物质的转化在给定条件下能实现的是()①NaAlO2(aq)AlCl3Al②NH3NO HNO3③NaCl(饱和)NaHCO3Na2CO3④FeS2SO3H2SO4.A.③④B.①④C.②④D.②③10.下列化学用语表达正确的是()A.碳酸钠的水解方程式:2H2O+CO32﹣⇌H2CO3+2OH﹣B.AlCl3溶液中加入过量氨水:Al3++4NH3•H2O═AlO2﹣+2H2O+4NH4+C.用过氧化氢从酸化的海带灰浸出液中提取碘:2I﹣+H2O2+2H+═I2+2H2OD.稀硫酸和氢氧化钡溶液反应:H++SO42﹣+OH﹣+Ba2+═BaSO4↓+H2O二、选择题(本题共10小题,每小题只有一个选项符合题意,每小题3分,共30分)11.下列物质的制备操作,可以达到实验目的是()A.向氯化铁溶液中不断加入氢氧化钠溶液制备氢氧化铁胶体B.用铜粉和硫粉混合加热制备硫化铜C.用铁做阳极电解硫酸钠溶液可以制得氢氧化亚铁D.向铝盐溶液中不断滴入过量烧碱溶液制备Al(OH)312.下列曲线表示卤族元素某种性质随核电荷数的变化趋势,正确的是()A.B.C.D.13.利用有机物X、Y合成广谱抗菌药物M的反应表示如图。