全国名市名校2019届甘肃省天水一中高三上学期一轮复习第五次质量检测(1月)数学(理)试题(word版)
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天水市一中2019届高三一轮复习第五次质量检测试题英语试题第I卷本试卷分为第I卷(选择题)和第II卷(非选择题)两部分。
时间:100分钟,分数:120分第一部分阅读理解阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。
AImagine you've had a fight with your best friend.It's a stupid fight,something you will both get over.But right now you are upset.When you walk in the door,your mum asks what's wrong.How are you mostly likely to respond? Have a long,comforting talk about it with her.Or head to the fridge for the ice cream.But can that really help you feel better—or just make you feel sickeningly full?Emotional eating is when people use food as a way to deal with feelings instead of to satisfy hunger.We've all been there,finishing a whole bag of chips or eating cookie after cookie while preparing for a coming exam.But when done a lot—especially without realizing it—emotional eating can affect weight,health,and well-being.One of the biggest beliefs about emotional eating is that it's caused by negative feelings.Yes,people often turn to food when they're stressed out,lonely,sad,anxious,or bored.Nevertheless,emotional eating can be linked to positive feelings too,like the romance of sharing dessert on Valentine's Day or the celebration of a holiday feast.More often,though,it's the countless little daily stresses that cause someone to seek comfort or relaxation in food.We all have our own comfort foods.Amazingly,they may vary according to moods and sex.One study found that happy people seem to want to eat things like pizza,while sad people prefer ice cream and cookies.Bored people desire salty,fragile things,like chips.Girls go for chocolate and ice cream.This brings up a curious question: Does no one take comfort in carrots and cabbages?Researchers are looking into that,too.What they're finding is that high-fat foods,like ice cream,may activate certain chemicals in the body that create a sense of contentment and fulfillment,which may actually make you reach for these foods again when feeling upset.We're all emotional eaters to some extent.But for some people,emotional eating can be a real problem,causing serious problems such as weight gain.Managing emotional eating means finding other ways to deal with the situations and feelings that make someone turn to food.For example,do you come home from school each day and automatically head to the kitchen? Stop and ask yourself,“Am I really hungry?” Are you having difficulty concentrating? If these signs point to hunger,choose something light and healthy to take the edge off until dinner.1. The first two paragraphs are designed to ________.A. offer advice on how to comfort an annoyed childB. explain the function of eating an ice creamC. put forward the idea of emotional eatingD. stress the importance of friendship2. People turn to emotional eating because ________.A. they suffer from weight problemsB. they want to seek comfort or relaxationC. they have a strong desire for foodD. they benefit a lot from eating3. Which of the following may not serve as comfort food?A. Cookies.B. Carrots.C. Chips.D. Pizzas.4. What's the main idea of the last paragraph?A. Eat whenever you can't concentrate.B. It is natural to feel hungry after school.C. It's hard to tell physical hunger from mental hunger.D. There are ways to break the cycle of emotional eating.【答案】1. C 2. B 3. B 4. D【解析】【分析】这是一篇说明文,介绍了“情绪饮食”这个概念,并对其进行了分析。
2019届天水市一中高三上学期一轮复习(1月)英语试卷第I卷本试卷分为第I卷(选择题)和第II卷(非选择题)两部分。
时间:100分钟,分数:120分第I卷第一部分阅读理解阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。
AImagine you've had a fight with your best friend.It's a stupid fight,something you will both get over.But right now you are upset.When you walk in the door,your mum asks what's wrong.How are you mostly likely to respond? Have a long,comforting talk about it with her.Or head to the fridge for the ice cream.But can that really help you feel better—or just make you feel sickeningly full?Emotional eating is when people use food as a way to deal with feelings instead of to satisfy hunger.We've all been there,finishing a whole bag of chips or eating cookie after cookie while preparing for a coming exam.But when done a lot—especially without realizing it—emotional eating can affect weight,health,and well-being.One of the biggest beliefs about emotional eating is that it's caused by negative feelings.Yes,people often turn to food when they're stressed out,lonely,sad,anxious,or bored.Nevertheless,emotional eating can be linked to positive feelings too,like the romance of sharing dessert on Valentine's Day or the celebration of a holiday feast.More often,though,it's the countless little daily stresses that cause someone to seek comfort or relaxation in food.We all have our own comfort foods.Amazingly,they may vary accordingto moods and sex.One study found that happy people seem to want to eat things like pizza,while sad people prefer ice cream and cookies.Bored people desire salty,fragile things,like chips.Girls go for chocolate and ice cream.This brings up a curious question: Does no one take comfort in carrots and cabbages?Researchers are looking into that,too.What they're finding is that high-fat foods,like ice cream,may activate certain chemicals in the body that create a sense of contentment and fulfillment,which may actually make you reach for these foods again when feeling upset.We're all emotional eaters to some extent.But for some people,emotional eating can be a real problem,causing serious problems such as weight gain.Managing emotional eating means finding other ways to deal with the situations and feelings that make someone turn to food.For example,do you come home from school each day and automatically head to the kitchen? Stop and ask yourself,“Am I really hungry?” Are you having difficulty concentrating? If these signs point to hunger,choose something light and healthy to take the edge off until dinner.1.The first two paragraphs are designed to ________.A.offer advice on how to comfort an annoyed child B.explain the function of eating an ice creamC.put forward the idea of emotional eating D.stress the importance of friendship2.People turn to emotional eating because ________.A.they suffer from weight problems B.they want to seek comfort or relaxationC.they have a strong desire for food D.they benefit a lot from eating3.Which of the following may not serve as comfort food?A.Cookies. B.Carrots. C.Chips. D.Pizzas.。
2019届天水市一中高三上学期第五次质量检测(1月)英语试卷第I卷本试卷分为第I卷(选择题)和第II卷(非选择题)两部分。
时间:100分钟,分数:120分第一部分阅读理解阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。
AImagine you've had a fight with your best friend.It's a stupid fight,something you will both get over.But right now you are upset.When you walk in the door,your mum asks what's wrong.How are you mostly likely to respond? Have a long,comforting talk about it with her.Or head to the fridge for the ice cream.But can that really help you feel better—or just make you feel sickeningly full?Emotional eating is when people use food as a way to deal with feelings instead of to satisfy hunger.We've all been there,finishing a whole bag of chips or eating cookie after cookie while preparing for a coming exam.But when done a lot—especially without realizing it—emotional eating can affect weight,health,and well-being.One of the biggest beliefs about emotional eating is that it's caused by negative feelings.Yes,people often turn to food when they're stressed out,lonely,sad,anxious,or bored.Nevertheless,emotional eating can be linked to positive feelings too,like the romance of sharing dessert on Valentine's Day or the celebration of a holiday feast.More often,though,it's the countless little daily stresses that cause someone to seek comfort or relaxation in food.We all have our own comfort foods.Amazingly,they may vary according to moods and sex.One study found that happy people seem to want to eatthings like pizza,while sad people prefer ice cream and cookies.Bored people desire salty,fragile things,like chips.Girls go for chocolate and ice cream.This brings up a curious question: Does no one take comfort in carrots and cabbages?Researchers are looking into that,too.What they're finding is that high-fat foods,like ice cream,may activate certain chemicals in the body that create a sense of contentment and fulfillment,which may actually make you reach for these foods again when feeling upset.We're all emotional eaters to some extent.But for some people,emotional eating can be a real problem,causing serious problems such as weight gain.Managing emotional eating means finding other ways to deal with the situations and feelings that make someone turn to food.For example,do you come home from school each day and automatically head to the kitchen? Stop and ask yourself,“Am I really hungry?” Are you having difficulty concentrating? If these signs point to hunger,choose something light and healthy to take the edge off until dinner.1. The first two paragraphs are designed to ________.A. offer advice on how to comfort an annoyed childB. explain the function of eating an ice creamC. put forward the idea of emotional eatingD. stress the importance of friendship2. People turn to emotional eating because ________.A. they suffer from weight problemsB. they want to seek comfort or relaxationC. they have a strong desire for foodD. they benefit a lot from eating3. Which of the following may not serve as comfort food?A. Cookies.B. Carrots.。
天水市一中 2019 届高三一轮复习第五次质量检测物理试题满分:100 分时间:90 分钟;一、选择题(1-9 单选,每题 3 分;10-12 多选,每题 4 分,共 39 分)1.三个相同的金属小球 a、b 和 c,原来 c 不带电,a 和 b 带等量异种电荷,相隔一定距离放置两球距离远大于球的半径,a、b 之间的静电力为 F,现将 c 球分别与 a、b 接触后拿开,a、b 距离不变,则a、b 之间的静电力将变为A. F B. F/2 C.F/4 D. F/82.如图所示,在一条直线上有两个相距 0.4m 的点电荷 A、B, A 带电+Q,B 带电-9Q 现引入第三个点电荷 C,恰好使三个点电荷均在电场力的作用下处于平衡状态,则 C 的带电性质及位置应为( )A负 A 的左边 0.2m 处 B.负 A 的右边 0.2m处C.正 B 的左边 0.2 m 处 D.B 的右边 0.4m处3.喷墨打印机的简化模型如图所示,重力可忽略的墨汁微滴,经带电室带负电后,以速度 v 垂直匀强电场飞入极板间,最终打在纸上,则微滴在极板间电场中()A.向负极板偏转B.电势能逐渐减小C.运动时间与电场强度大小有关D.运动轨迹与所带电荷量无关4.如图,一带正电的点电荷固定于 O 点,两虚线圆均以为 O 圆心,两实线分别为带电粒子 M和 N 先后在电场中运动的轨迹,a、b、c、d、e 为轨迹和虚线圆的交点。
不计重力。
下列说法说法正确的是()A.N 在 d 点的电势能等于它在 e 点的电势能B. M 在 b 点的加速度大小大于它在 a 点的加速度大小C. N 在从 e 点运动到 d 点的全过程中,电场力始终不做功D.对同一虚线圆上的点 a 和 c,电场强度相同5.电荷量不等的两点电荷固定在 x 轴上坐标为-3L 和 3L 的两点,其中坐标为-3L 处点电荷带电量绝对值为 Q,两点电荷连线上各点电势随 x 变化的关系如图所示,其中 x=L 处电势最低,x 轴上M、N 两点的坐标分别为-2L 和 2L,则下列判断正确的是( )A.两点电荷一定为异种电荷B.原点 O 处场强大小为C.正检验电荷在原点 O 处收到向左的电场力D.负检验电荷由 M 点运动到 N 点的过程,电势能先减小后增大6.一只电流表的满偏电流,内阻,把它改装成量程为的电压表,下列说法中正确的是( )A.需串联一个1500Ω的电阻 B.需串联一个 1000Ω的电阻C.需并联一个1000Ω的电阻 D.改装后,电压表的内阻为1000Ω7.如图所示,两盏相同的灯泡在电路闭合都能正常发光。
2019届甘肃省天水市一中高三上学期第五次月考英语试卷注意事项:1.答题前,先将自己的姓名、准考证号填写在试题卷和答题卡上,并将准考证号条形码粘贴在答题卡上的指定位置。
2.选择题的作答:每小题选出答案后,用2B铅笔把答题卡上对应题目的答案标号涂黑,写在试题卷、草稿纸和答题卡上的非答题区域均无效。
3.非选择题的作答:用签字笔直接答在答题卡上对应的答题区域内。
写在试题卷、草稿纸和答题卡上的非答题区域均无效。
4.考试结束后,请将本试题卷和答题卡一并上交。
第I卷(选择题)一、阅读理解Imagine you've had a fight with your best friend.It's a stupid fight,something you will both get over.But right now you are upset.When you walk in the door,your mum asks what's wrong.How are you mostly likely to respond? Have a long,comforting talk about it with her.Or head to the fridge for the ice cream.But can that really help you feel better—or just make you feel sickeningly full?Emotional eating is when people use food as a way to deal with feelings instead of to satisfy hunger.We've all been there,finishing a whole bag of chips or eating cookie after cookie while preparing for a coming exam.But when done a lot—especially without realizing it—emotional eating can affect weight,health,and well-being.One of the biggest beliefs about emotional eating is that it's caused by negative feelings.Yes,people often turn to food when they're stressed out,lonely,sad,anxious,or bored.Nevertheless,emotional eating can be linked to positive feelings too,like the romance of sharing dessert on Valentine's Day or the celebration of a holiday feast.More often,though,it's the countless little daily stresses that cause someone to seek comfort or relaxation in food.We all have our own comfort foods.Amazingly,they may vary according to moods and sex.One study found that happy people seem to want to eat things like pizza,while sad people prefer ice cream and cookies.Bored people desire salty,fragile things,like chips.Girls go for chocolate and ice cream.This brings up a curious question: Does no one take comfort in carrots and cabbages?Researchers are looking into that,too.What they're finding is that high-fat foods,like ice cream,may activate certain chemicals in the body that create a sense of contentment and fulfillment,which may actually make you reach for these foods again when feeling upset.We're all emotional eaters to some extent.But for some people,emotional eating can be a real problem,causing serious problems such as weight gain.Managing emotional eating means finding other ways to deal with the situations and feelings that make someone turn to food.For example,do you come home from school each day and automatically head to the kitchen? Stop and ask yourself,“Am I really hungry?” Are you having difficulty concentrating? If these signs point to hunger,choose something light and healthy to take the edge off until dinner.1.The first two paragraphs are designed to ________.A.offer advice on how to comfort an annoyed childB.explain the function of eating an ice creamC.put forward the idea of emotional eatingD.stress the importance of friendship2.People turn to emotional eating because ________.A.they suffer from weight problemsB.they want to seek comfort or relaxationC.they have a strong desire for foodD.they benefit a lot from eating3.Which of the following may not serve as comfort food?A.Cookies. B.Carrots.C.Chips. D.Pizzas.4.What's the main idea of the last paragraph?A.Eat whenever you can't concentrate.B.It is natural to feel hungry after school.C.It's hard to tell physical hunger from mental hunger.D.There are ways to break the cycle of emotional eating.In New York,Ma witnessed the Alibaba Group opening on the New York stock exchange with the largest initial public offering (IPO,新股发行) in American history.“Alibaba,the world's largest Internet commerce company makes China equal to the US in the rapidly increasing global competition for technological innovation (创新) and economic transformation,” commented the South China Morning Post.It has also made Ma China's richest man with a fortune of around $25 billion (153 billion yuan),reported Reuters.It's reported that Ma's rags-to-riches journey is just as spectacular as his Internet empire.Ma failed the national college entrance exams twice before he was finally in Hangzhou Normal University on his third attempt and failed in finding a suitable job several times.Aslo,Mr Ma is a big believer in perseverance,which was proved in his English study experience.However,it was his vision and goals that launched his career.During a short trip to the US as an interpreter in 1995,Ma first experienced the Internet.He believed in the Internet's business potential when few other Chinese people did.He started Alibaba in his Hangzhou apartment,with 17 friends and $60,000 of funds.At the time,when e-commerce was unheard of in China,“I_called_myself_a_blind_man_riding_on_the_back_of_blind_tigers,” he once said,according to The Guardian.His unusual ideas earned him the nickname “Crazy Jack Ma”.Indeed,Ma is different.Although he is very thin and about 160cm tall,“Ma is yet animated and forceful,” said The Guardian.He is funny,creative,and a compelling (引人注目的) speaker.Ma told Time magazine that he was “old for the Internet”.He started to slow down and looked around.According to The Wall Street Journal,Ma plans to open a tai chi club with the actor Jet Li,build an entrepreneur (企业家) university in Hangzhou and continue to work on several environmental projects.5.What made him into e-commerce industry?A.His foresight and ambitions. B.His English learning experience.C.His belief in perseverance. D.His 17 friends and$60,000 funds.6.What does the underlined sentence in Paragraph 5 mean?A.Ma is a blind man riding on a blind tiger. B.Ma knew little about e-commerce.C.Ma had no confidence in his business future. D.Ma had not enough money at that time.7.What's the personality of Ma Yun according to the passage?A.Determined and creative. B.Funny and competitive.C.Rich and different. D.Attractive and believable.8.What's the best title of the passage?A.The development of Alibaba Group B.Ma Yun's personal lifeC.E-commerce in China D.Ma Yun's crazy successGuests arriving at the Aloft Hotel in Manhattan or one in Silicon Valley will soon be able to do something hotels have dreamed about offering for years: walk past the check-in desk and enter their rooms by using a smartphone as a room key. The boutique hotel brand from Starwood to Hotels & Resorts Worldwide Inc. plans to offer this feature at two hotels, in the Harle neighborhood and in Cupertino, Calif, before the end of the quarter.Starwood officials are hoping this will be one of the biggest technological changes in the industry since free Wi-Fi. "We believe this will become the new standard for how people will want to enter a hotel." says Frits van Passchen, Starwood's CEO. "It may be a novelty at first,but we think it will become table stakes for managing a hotel.Not everyone is so sure. Past attempts to use technology to streamline the check-in process have had mixed results. Robert Habeeb, president of the。
天水市一中2019届高三一轮复习第五次质量检测数学试题(文科)一、单选题。
1.已知集合,,则()A. B. C. D.【答案】C【解析】【分析】先求解集合B,然后由集合的交集运算求解.【详解】因为,所以,故选C.【点睛】本题考查了对数不等式的解法、集合交集运算,属于基础题,题目意在考查对集合运算掌握的熟练程度.2.已知等差数列{a n}的前n项和为S n,若6a3+2a4-3a2=15,则S7=( )A. 7B. 14C. 21D. 28【答案】C【解析】【分析】由已知式子可得的值,由等差数列的求和公式和性质可得,代值计算即可.【详解】设等差数列的公差为,因为,所以,化简得,即,所以,故选C.【点睛】本题主要考查了等差数列的求和公式,及等差数列的性质的应用,其中解答中根据题设条件化简得到的值是解答的关键,着重考查了推理与运算能力,属于基础题.3.己知某个几何体的三视图如图,根据图中标出的尺寸(单位:),可得这个几何体的体积是()A. B. C. D.【答案】B【解析】【分析】三视图可知,该几何体为三棱锥,分别确定底面积和高,利用锥体的体积公式求解即可.【详解】由三视图可知,该几何体为三棱锥,底面为等腰三角形,如图:由俯视图知底面等腰三角形的高为2,底边长为2,∴S底面2×2=2,∴由正视图知棱锥的高2.∴三棱锥的体积为V2×2.故选:B.【点睛】本题考查三视图及其应用,棱锥的体积计算,关键是利用三视图判断几何体的形状与相关数据,属于中等题.4.若变量x,y满足约束条件,则的最大值是()A. 0B. 2C. 5D. 6【答案】C【解析】【分析】画出不等式组表示的可行域,令,则,平移直线到可行域,根据的几何意义确定出最优解,然后可得的最大值.【详解】画出不等式组表示的平面区域,如图阴影部分所示.令,则,平移直线,结合图形可得,当直线经过可行域内的点A时,直线在y轴上的截距最大,此时取得最大值.由,得,∴点A的坐标为,∴.故选C.【点睛】(1)利用线性规划求目标函数最值的步骤①作图:画出约束条件所确定的平面区域和目标函数所表示的平面直线系中的任意一条直线;②平移:将平行移动,以确定最优解所对应的点的位置.有时需要进行目标函数和可行域边界的斜率的大小比较;③求值:解有关方程组求出最优解的坐标,再代入目标函数,求出目标函数的最值.(2)用线性规划解题时要注意的几何意义,分清与直线在y轴上的截距成正比例还是反比例.5.函数的部分图象如图所示,则()A. B.C. D.【答案】B【解析】【分析】由函数的图象可得,可解得;再由“五点作图法”解得,从而可得 .【详解】由函数的图象可知,,故,解得,由“五点作图法”得,解得,,故选B.【点睛】本题主要通过已知三角函数的图象求解析式考查三角函数的性质,属于中档题.利用最值求出 ,利用图象先求出周期,用周期公式求出,利用特殊点求出,正确求是解题的关键.求解析时求参数是确定函数解析式的关键,由特殊点求时,一定要分清特殊点是“五点法”的第几个点,用五点法求值时,往往以寻找“五点法”中的第一个点为突破口,“第一点”(即图象上升时与轴的交点)时;“第二点”(即图象的“峰点”)时;“第三点”(即图象下降时与轴的交点)时;“第四点”(即图象的“谷点”)时;“第五点”时.6.已知下列不等式①②③④⑤中恒成立的是( )A. 1个B. 2个C. 3个D. 4个【答案】C【解析】【详解】取,则不成立;由指数函数的单调性可知成立;取,则不成立;对于任意的,都有成立;由于底数成立,故五个命题中有三个是正确的,应选答案C。
天水市一中2019届高三一轮复习第五次质量检测化学试题(满分:100分时间:90分钟)可能用到的相对原子质量:H-1 C-12 N-14 O-16 Mg-24 Al-27 Cu-64一、选择题(每题2分,共20题)1.N A代表阿伏加德罗常数的值,下列叙述正确的是( )A. 9g超重水(3H216O)含中子数为6N AB.标准状况下,22.4L CCl4含有的分子数目为N AC. 78g过氧化钠中含有的阴阳离子总数为4N AD. 28g乙烯与聚乙烯的混合物完全燃烧生成水的分子数为2N A2.下列根据实验现象所得出的结论中,正确的是()A.无色溶液中加入稀盐酸产生无色无味气体,该气体能使澄清石灰水变浑浊,结论:原溶液可能含有CO32-B.某物质焰色反应呈黄色,结论:该物质是钠盐C.无色试液加入NaOH溶液,加热产生的气体使红色石蕊试纸变蓝,结论:试液中含NH3D.无色溶液中加入BaCl2溶液有白色沉淀产生,再加盐酸,沉淀不消失,结论:原溶液一定含有SO42-3.下列依据热化学方程式得出的结论正确的是( )A.已知:P(白磷,s)=P(红磷,s)△H<0,则白磷比红磷稳定B.已知2H2(g)+O2(g)=2H2O(g)△H= -483.6kJ•mol-1,则氢气的标准燃烧热为241.8kJ•mol-1C.已知:2C(s)+2O2(g)=2CO2(g)△H=a kJ•mol-12C(s)+O2(g)=2CO(g)△H=b kJ•mol-1,则a>bD.已知:NaOH(aq)+HCl(aq)=NaCl(aq)+H2O(l)△H=-57.3kJ•mol-1,则含40.0gNaOH的稀溶液与浓硫酸完全中和,放出大于57.3 kJ的热量4.氢气(H2)、一氧化碳(CO)、辛烷(C8H18)、甲烷(CH4)燃烧的热化学方程式分别为:( )H2(g)+1/2O2(g)===H2O(l) ΔH=-285.8 kJ/molCO(g)+1/2O2(g)===CO2(g) ΔH=-283.0 kJ/molC8H18(l)+25/2O2(g)===8CO2(g)+9H2O(l) ΔH=-5518 kJ/molCH4(g)+2O2(g)===CO2(g)+2H2O(l) ΔH=-890.3 kJ/mol相同质量的H2、CO、C8H18、CH4完全燃烧时,放出热量最少的是( )A. H2(g) B. CO(g) C. C8H18(l) D. CH4(g)5.下列叙述正确的是( )A. F比S的非金属性强,故F的最高价氧化物对应的水化物的酸性大于硫酸B.因为H2O比H2S稳定,所以H2O比H2S的沸点要高一些C.如果n为第ⅡA族中某元素的原子序数,则原子序数为(n+1)的元素可能位于第ⅢA族或ⅢB族D.含有共价键的化合物可能是离子化合物,含有离子键的化合物可能是共价化合物6. 短周期主族元素X、Y、Z、W原子序数依次增大,其中X与Y同周期且相邻,Y与W均可形成18个电子的氢化物,且两者可反应生成淡黄色固体,Z是地壳中含量最高的金属元素。
天水市一中2019届高三一轮复习第五次质量检测
数学试题(理科)
(满分:150分时间120分钟)
一、单选题(每小题5分,共60分)
1.已知集合,,则()
A.B.C.D.
2.已知等差数列{a n}的前n项和为S n,若6a3+2a4-3a2=15,则S7=( )
A.7 B.14 C.21 D.28
3.己知某个几何体的三视图如图,根据图中标出的尺寸(单位:),可得这个几何体的体积是()
A.B.C.D.
4.若变量x,y满足约束条件,则的最大值是()
A.0B.2C.5D.6
5.函数的部分图象如图所示,则()
A.B.
C.D.
6.已知下列不等式①②③④⑤中恒成立的是( ) A.1个B.2个C.3个D.4个
7.若是两条不同的直线,是两个不同的平面,则下列命题正确的是()
A.若,则B.若,则
C.若,则D.若,则
8.已知向量,,满足,,,,分别是线段,的中点,若,则向量与的夹角为()
A .
B .
C .
D .
9.如图,棱长为1的正方体ABCD-A 1B 1C 1D 1中,为线段A 1B 上的动点,则的最小值为( )
A .
B .
C .
D .
10.在ABC ∆中,角A B C ,,所对应的边长分别为a b c 、、,若sin sin 2sin a A b B c C +=,则cos C 的最小值为( )
A .
B .
C . 12
D . 12-
11.双曲线()的左、右焦点分别为,过作圆的切线交双曲线的左、
右支分别于点B 、C ,且|BC|=|CF 2|,则双曲线的渐近线方程为( )
A .
B .
C .
D .
12.函数的定义域为实数集,,对于任意的都有,若在区
间
函数恰有三个不同的零点, 则实数的取值范围是( )
A .
B .
C .
D .
二、填空题(每小题5分,共20分)
13.已知命题p :,命题q :1-m≤x≤1+m ,m >0,若q 是p 的必要而不充分条件,则m 的取
值范围为________.
14.春节期间,某销售公司每天销售某种取暖商品的销售额(单位:万元)与当天的平均气温(单位:℃)有关.现收集了春节期间这个销售公司天的与的数据列于下表:
由以上数据,求得与之间的线性回归方程的系数,则 __________
15.若直线与曲线恰有一个公共点,则实数m的取值范围为.
16.抛物线的焦点为,过点的直线交抛物线于,两点,交抛物线的准线于点,若
,,则__________.
三、解答题(共6题,共70分)
17.(10分)在锐角中,、、分别为角、、所对的边,且.
(1)确定的大小;
(2)若,且的周长为,求的面积.
18.(12分)已知数列的前项和满足.
(1)求数列的通项公式;
(2)设,求数列的前项和.
19.(12分)某机构为了解某地区中学生在校月消费情况,随机抽取了 100名中学生进行调查.如图是根据
调査的结果绘制的学生在校月消费金额的频率分布直方图.已知三个金额段的学生人数成等差数列,将月消费金额不低于550元的学生称为“高消费群”.
(1)求的值,并求这100名学生月消费金额的样本平均数(同一组中的数据用该组区间的中点值作代表);
(2)根据已知条件完成下面列联表,并判断能否有的把握认为“高消费群”与性别有关?
附: (其中样本容量)
20.(12分)在如图所示的几何体中,平面,四边形为等腰梯形,,
.
(1)证明:;
(2)求二面角
的余弦值.
21.(12分)已知椭圆的左、右焦点分别为,若椭圆经
过点
,且
的面积为.
(1)求椭圆的标准方程;
(2)设斜率为的直线与以原点为圆心,半径为
的圆交于
两点,与椭圆交于
两点,且
,当取得最小值时,求直线的方程并求此时的值.
22.(12分)已知函数()ln 1a
f x x x
=+
-, a R ∈. (Ⅰ)若曲线()y f x =在点()()
1,1f 处的切线与直线10x y -+=垂直,求函数()f x 的极值; (Ⅱ)设函数()1
g x x x
=+
.当1a =-时,若区间[]1,e 上存在0x ,使得()()001g x m f x ⎡⎤<+⎣⎦,求实数m 的取值范围.(e 为自然对数底数)
天水市一中2019届高三一轮复习第五次质量检测
数学试题答案(理科)
一、单选题(每小题5分,共60分)
CCBCB CDBBC CD
二、填空题(每小题5分,共20分)
13.14.15.或16.1或3三、解答题(共6题,共70分)
17.(1)因为,由正弦定理得,
因为,所以.
所以或.
因为是锐角三角形,所以.
(2)因为,且的周长为,所以①
由余弦定理得,即②
由②变形得,所以,
由面积公式得.
18.(1);(2).
(1)当时,;
当时,,符合上式.综上,.
(2).则
由(1)-(2)得
故.
19.((1)由题意知且
解得
所求平均数为(元)(2)根据频率分布直方图得到如下列联表
根据上表数据代入公式可得
所以没有的把握认为“高消费群”与性别有关.
20.(1)由题知平面,平面,
过点A作于,在中,,
在中,
且平面又平面
(2)以A为坐标原点,AB,AC,AE分别为轴,建立空间直角坐标系,
则
设为平面BEF 的一个法向量,则令得,
同理可求平面DEF 的一个法向量,,
所以二面角的余弦值为.
23.解:(1)由的面积可得:①
又椭圆过点,②
由①②解得,所以椭圆标准方程为
(2)设直线的方程为,则原点到直线的距离
所以
将代入椭圆方程,得
由判别式
,解得
由直线直圆相交得,所以
设,则
所以
所以,因为,所以
则当时,取得最小值,此时直线方程为.
25.(1)()()2210a x a
f x x x x x
-=
-=>',
因为曲线()y f x =在点()()
1,1f 处的切线与直线10x y -+=的垂直, 所以()11f '=-,即11a -=-,解得2a =. 所以()22
x f x x
=
'-. ∴当()0,2x ∈时, ()0f x '<, ()f x 在()0,2上单调递减; 当()2,x ∈+∞时, ()0f x '>, ()f x 在()2,+∞上单调递增; ∴当2x =时, ()f x 取得极小值()2
2ln21ln22
f =+-=, ∴()f x 极小值为ln2. (2)令()()11h x x m f x x ⎡⎤=+
-+=⎣⎦ 1ln m
x m x x x
+-+, 则()()()2
11x m x h x x ⎡⎤⎣⎦'-++=,欲使在区间上[]1,e 上存在0
x ,使得()()00g x mf x <,
只需在区间[]
1,e 上()h x 的最小值小于零. 令()0h x '=得, 1x m =+或1x =-.
当1m e +≥,即1m e ≥-时, ()h x 在[]
1,e 上单调递减,则()h x 的最小值为()h e ,
∴()10m
h e e m e +=+-<,解得211e m e +>-, ∵2111e e e +>--,∴211
e m e +>-; 当11m +≤,即0m ≤时, ()h x 在[]
1,e 上单调递增,则()h x 的最小值为()1h , ∴()1110h m =++<,解得2m <-,∴2m <-;
当11m e <+<,即01m e <<-时, ()h x 在[]1,1m +上单调递减,在(]
1,m e +上单调递增, 则()h x 的最小值为()1h m +,
∵()0ln 11m <+<,∴()0ln 1m m m <+<.
∴()()12ln 12h m m m m +=+-+>,此时()10h m +<不成立.
综上所述,实数m 的取值范围为()21,2,1e e ⎛⎫+-∞-⋃+∞ ⎪-⎝⎭。