2019数学考研一真题

去百度文库，查看完整内容>内容来自用户:GG135795959862019年考研数学一真题解析一、选择题1—8小题．每小题4分，共32分．1．当时，若与是同阶无穷小，则（）（A）（B）（C）（D）【答案】（C）【详解】当时，，所以，所以．2．设函数，则是的（）（A）可导点，极值点（B）不可导的点，极值点（C）可导点，非极值点（D）不可导点，非极值点【答案】（B）【详解】（1），所以函数在处连续；（2），所以函数在处不可导；（3）当时，，函数单调递增；当时，，函数单调减少，所以函数在取得极大值．3．设是单调增加的有界数列，则下列级数中收敛的是（）（A）（B）(C）（D）【答案】（D）【详解】设是单调增加的有界数列，由单调有界定理知存在，记为；又设，满足，则，且，则对于正项对于级数，前项和：也就是收敛．4．设函数，如果对于上半平面内任意有向光滑封闭曲线都有那么函数可取为（）（A）（B）（C）（D）【答案】（D）【详解】显然，由积分与路径无关条件知，也就是，其中是在上处处可导的函数．只有（D）满足．5．设是三阶实对称矩阵，是三阶单位矩阵，若，且，则二次型的规范形是（）（A）（B）（C）（D）【答案】（C）【详解】假设是矩阵的特征值，由条件可得，也就是矩阵（设函数分别求解线性方程组

去百度文库，查看完整内容>内容来自用户:惹我反倒是2019年考研数学一真题解析一、选择题，1~8小题，每小题4分，共32分.下列每题给出的四个选项中，只有一个选项是符合题目要求的.1.当x0时，若xtanx与xk是同阶无穷小，则kA.1.B.2.C.3.D.4.【答案】C【答案解析】根据泰勒公式有xtanx~1x3，故选C.3对泰勒不熟悉的同学，本题也可以用洛必达法则.xx,x0,2.设函数f(x)则x0是f(x)的xlnx,x0,A.可导点，极值点.B.不可导点，极值点.C.可导点，非极值点.D.不可导点，非极值点.【答案B】xlnx0【答案解析】由于lim不存在（极限为无穷属于极限不错在），故x0是f(x)的x0x不可导点.且当x0,f(x)0;0x1,f(x)0且f(0)0，由极值定义可知，x0是f(x)的极值点，故选B.3.设un是单调增加的有界数列，则下列级数中收敛的是A.un.n1nB.(1)n1.n1unC.n11unun1.D.u2n1un2.n1【答案】D【答案解析】选项A：un单调递增有界，知un收敛,故limnunu0，也就是n趋近无穷时，un1,故根据极限形式的比较审敛发，un与1同敛散，而1发散，故选项nnn1nn1nn1

2019考研数学真题都是在考试之后才能公布，因此之前看到的多数都是押题或者往年的题。具体还需要这两天22号，23号考试结束之后才会公布出来哦。可以第一时间获取考研真题解析直播视频的，请查看我们官网的消息哦。不要错过。

去百度文库，查看完整内容>内容来自用户:好读书不求甚解2019年全国硕士研究生入学统一考试数学二试题一、选择题：1~8小题，每小题4分，共32分。下列每题给出的四个选项中，只有一个选项是符合题目要求的.（1）当x0时，若xtanx与xk是同阶无穷小，则k=（）(A)1(B)2(C)3(D)4（2）曲线yxsinx2cosx(x2)的拐点是（）2(A)(0,2)(B)(,2)(C)(，)22(D)(3，3)22（3）下列反常积分发散的是（）(A)xexdx0(C)0arctan1x2xdx(B)xex2dx0(D)01xx2dx（4）已知微分方程yaybycex的通解为y(C1C2x)exex,则a,b,c依次为（）(A)1,0,1(B)1,0,2(C)2,1,3(D)2,1,4（5）已知平面区域D(x,y)xy2,记I1Dx2y2dxdy,I2sinDx2y2dxdy,I3(1cosx2y2)dxdy则（）D(A)I3I2I1(B)I2I1I3(C)I1I2I3(D)I2I3I1（6）设函数f(x),g(x)的2阶导函数在xa处连续，则limxaf(x)g(x)(xa)20是两条曲线yf(x),yg(x)在xa对应的点处相切及曲率相等的（）(A)充分不必要条件(C)必要不充分条件(B)充分必要条件(D)既不充分也不必要条件（

不是19，但是最新的链接： 提取码：84z6

现在不需要做真题吧，先考虑一下报考的专业和院校吧，熟悉一下考研关键时间，做个全年的计划。多上论坛看看你报考院校专业的经验贴。考研越到后面时间越紧，初期时间很宽松，可先看看政治英语数学这类公共课，政治大致看一下基本原理，英语可先从单词长难句开始，专业课到你最终确定院校了再购买专业课书.

看你找什么工作了，教师的工作还有点时间学习，一般情况工作了就没时间复习了。而且复习了也没气氛，还三心二意的，想着工作还想着考研。如果工作稳定了你考研考上了你又不舍的放弃好工作概率一样的，看自个了。身边好多工作后考上的更多追答今年考上和明年一样吗？追答一样的，对你自己而言，可能不一样，因为你工作了一年，心境不一样，工作一年的话明年考，成绩能提高吗？追答看你个人努力了

时间总是不等人的

9月参加雅思考试的勇士们 首要面对的一大难题就是： 雅思口语新题！ 何为变题？ 每年1、5、9月为雅思口语变题季 包括 Part1、Part2、Part3 雅思口语话题会淘汰30%~40%旧题 并补充相应数量的新题！ 变题季的题目无非就是以下3种 1. 新题—— 全新题，出现频次一般较高，重中之重！ 2. 旧题回库—— 去年或者是考过的题，回归到了题库，那就意味着9~12月会继续考，后期备考学生们要留意了。 3. 重点老题—— 为各大考场出现频次极高的题，要重点准备~ 9~12月雅思口语完整题库 新题+保留旧题 都get了吗？？？ 还没有拿到的烤鸭不要急走一波！ 你没有看错哦，是 口！语！题！库！ 有了这份雅思口语题库 接下来你们的 雅思口语分数将会直线飙升！ 全部！ 免费！ 送给你！ 换题季初期只要好好准备 抽到原题的几率敲大呦 Part1 1.Haircut (1)Have you ever had an unhappy haircut experience? (2)How long have you had your current haircut? (3)How often do you have a haircut? (4)Do you like having your hair cut? (5)What’s your last haircut? 2.Jeans (1)Do you wear jeans? (2)How often do you wear jeans? (3)Do you like wearing jeans, why? (4)Why do you think jeans are popular? (5)Do you spend a lot on jeans? 3.Voice (1)Do you like your own voice? (2)Has your voice ever changed? (3)Do you enjoy recording your voice and listening to it? 4.Concentration (1)When do you need to be focused? (2)What may distract you when you are trying to stay focused？ (3)What do you do to help you concentrate? (4)Is it difficult for you to stay focused on something? 5.Walking (1)Do you walk a lot? (2)Do you walk more often than in the past? (3)Do you think people will take a walk more often or not? 6.Languages (1)What languages can you speak? (2)Do you think it’s difficult to learn a new language? (3)Will you learn other languages in the future? Part2&3 1.科技产品 Describe an important technological proct you bought You should say: What it is How you use it Why you bought it And explain why you think it is important (1)What do you think is the most important equipment in the workplace? (2)Which technological proct do you think is most useful at home? (3)Do you think there will be no teachers to teach in schools in the future? (4)Do you think some technological procts make people lazier? Why? 2.人工智能 Describe a proct or application which is based on artificial intelligence You should say: What it is What it is used for How it is used And explain what you think of it (1)How will artificial intelligence affect our lives? (2)Will artificial intelligence have emotions in the future? 3.去过的城市 Describe a city you once went to with your family You should say: What the city was Why you went there What the city was like And explain how you felt about it (1)What kind of city do you like? (2)What are the advantages of living in a city? (3)Why do many people nowadays prefer living in the suburbs? 4.教老年人 Describe a time when you taught an older person something new You should say: When it happened Who you taught Why you taught this person And explain how you felt about it (1)Do you think old people know more things than young people? (2)Is it easy for old people to use new technology? (3)Why do some old people refuse to use new technology? (4)What are the advantages and disadvantages for old people to use smart-phones? 5.开车旅行 Describe a journey that you went on by car You should say: When was is Where you went Who you were with And how you felt about the journey (1)Do you think cars are a daily necessity? (2)What will cars look like in the future? (3)Is driving a skill that everybody must learn? (4)What are the downsides of having a car? ......... 篇幅有限，小秘书就不一一贴出来了 获取完整版请添加朗阁小秘书微信号 打call 打call 打call 领取方式 获取完整PDF版请关注“北京朗阁培训中心”微信公众号，添加朗阁小秘书为好友，回复“口语”，即可免费领取！