江西理工大学数学专业英语考试重点2
数学专业英语翻译2-7

7-B The limit of a sequence
The main question we are concerned with here is to decide whether or not the terms f(n) tend to a finite limit as n increases infinitely. 这里我们关心的主要问题是当n无限增加时,项 f(n) 是否会趋于一个有限的极限。
如果对每一个正整数 n都有一个实数或复数an与之对 应, 则有序集a1 , a2, …, an ,… 称为一个无穷序列.
The important thing here is that each member of the set has been labeled with an integer so that we may speak of the first term a1, the second term a2, and, in general, the nth term an. 这里重要的是集合中的每一个元素都由一个整数标 记,因此我们可以说第一项 , 第二项, 一般的,第n项
This particular rule is known as a recursion formula and it defines a famous sequence whose terms are called Fibonacci numbers. The first few terms are 1,1,2,3,5,8,13,21,34. 这个特殊的规则就是常见的递推公式,它定义了一个 著名的序列,其中的项称为菲波那契数。前几项是…...
江西理工大学高数下期末复习二

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江西理工大学高等数学(二)答案

《高等数学》试题解答一、填空题:(3×5=15分)1.设y x z =,则=∂∂yz x x y ln . 2. 积分=⎰⎰Dxydxdy 16 ,其中D 为40 ,20≤≤≤≤y x .3. L 为2x y =点(0, 0)到(1, 1)的一段弧,则=⎰ds y L []155121-. 大根号4x^2+1 4. 级数∑∞=-1)1(n p nn 当p 满足10≤<p 时条件收敛. 5. 方程0)1(=+-dy e dx ye x x 的通解为)1(x e C y +=.分离变量二、选择题:(3×5=15分)1.方程0)4(sin )cos 3(32=-++dy y x dx x y x 是 ( C ). x Q y P ∂∂=∂∂(A) 可分离变量微分方程 (B) 一阶线性方程(C) 全微分方程 (D) (A )、(B )、(C )均不对 2.),(y x f z =在),(00y x 可微,则yz x z ∂∂∂∂ ,在) ,(00y x ( D ). (A )连续 (B )不连续 (C )不一定存在 (D )一定存在3.级数∑∞=⎪⎪⎭⎫ ⎝⎛+--21111n n n 是( A ). ∑∞=-212n n (A )发散 (B )收敛(C )条件收敛 (D )绝对收敛4.曲面22y x z +=与平面1=z 所围立体的体积为( B ).(A )⎰⎰⎰+Ωdv y x )(22; (B )⎰⎰⎰11 02 0 r πdz rdr θd ;“先一后二”(C )⎰⎰⎰+----2222 0 1 1 1 1 y x x x dz dy dx ; (D )⎰⎰⎰10 1 0 2 0 dz rdr θd π。
5.方程x e x y y y -=+'-''323的特解形式为( B ).(A )x e b ax )(+ (B )x cxe b ax ++(C )x ce b ax ++ (D )x xe b ax )(+三、)(22x y f z -=,其中)(u f 有连续的二阶偏导数,求22x z ∂∂.(8分) 解:)2()(22x x y f z x -⋅-'=)2()(2)2()(2222x x y f x x y f z xx -⋅-''--⋅-'= )(4)(222222x y f x x y f -''+-'-=四、计算⎰-+-Lx x dy y e dx y y e )2cos ()2sin (,L 为由点)0 ,1(A 到)1 ,0(B ,再到)0 ,1(-C 的有向折线.(8分) 解:作11 ,0:≤≤-=x y CA ,……………….1分⎰=ABCA []d xdy y e y e D x x ⎰⎰--)2cos (cos =2⎰⎰D dxdy =2, 0 ⎰=CA2=∴I五、计算⎰⎰++∑dxdy zx dzdx yz dydz xy 222,其中∑为球体4222≤++z y x 及锥体22y x z +=的公共部分的外表面.(8分) 解:()d xdydz x z y I ⎰⎰⎰Ω++=222⎰⎰⎰ππϕϕθ=2044020sin dr r d d ⎪⎪⎭⎫ ⎝⎛-=221564π六、求级数∑∞=22n n nx 的收敛域及和函数.(8 分)解:收敛域为:)1 ,1(-=)(x S ∑∞=22n n nx ∑∞=-=212n n nx x '⎪⎭⎫ ⎝⎛=∑∞=22n n x x ='⎪⎭⎫ ⎝⎛---x x x 1112⎥⎦⎤⎢⎣⎡--=1)1(122x x 七、计算曲面积分⎰⎰+∑dS y x )(22,其中∑为锥面)(322y x z +=被平面3=z截下的带锥顶的部分.(8分) 解:dxdy y x y y x x y x I xy D ⎰⎰+++++=22222222331)( ⎰⎰+=xyD dxdy y x )(222⎰⎰πθ=303202dr r d π=9八、求函数22y x z +=在适合条件132=+y x 下的极小值.(7分) 解:作⎪⎭⎫ ⎝⎛-+++=132),,(22y x y x y x f λλ ⎪⎪⎪⎩⎪⎪⎪⎨⎧=-+==λ+==λ+=λ0132032022y x f xy f x f y x 1372-=λ,1312,1318==∴y x 1336min =z 九、求方程x e y y y 323=+'-''的通解.(8分) 解:特征方程:0232=+-r r特征根:2,121==r r对应齐次方程的通解为:x x e C e C Y 221+= 1=λ是单根,可设非齐次方程的特解为x Axe y =* 代入原方程得:x xe y A 3,3*-=∴-= 原方程的通解为:x x x xe e C e C y 3221-+=十、把)0( ,)(π<<=x x x f 展开为余弦级数.(7分) 解:π=π=⎰π002xdx a ⎪⎩⎪⎨⎧-==⎰为偶数为奇数n n n nxdx x a n 0 4cos 220πππ ∑∞=π<<-π--π=120 ,)12cos()12(42n x x n n x 十一、已知曲线积分⎰+⎥⎦⎤⎢⎣⎡+++),()0,0()()(1)1(y x n x dy x f ydx x f x n x e 与路径无关, 其中)(x f 可微,0)0(=f ,试确定)(x f ,并计算曲线积分的值.(8分) 解:依题意有:)()(1)1(x f x f x n x e n x '=+++ 讨论 )()(1x f x f x n '=+ n x C x f )1()(+=令)(x C C =,利用常数变易法得:C e x C x +=)( n x n x e x C x f )1()1()(+++=∴由10)0(-=⇒=C f)1()1()(-+=∴x n e x x f)()(0x yf dy x f I y==⎰。
新版江西理工大学数学考研经验考研真题考研参考书

考研是一项小火慢炖的工程,切不可操之过急,得是一步一个脚印,像走长征那样走下来。
在过去的一年中,我几乎从来没有在12点之前睡去过。
也从来也没有过睡到自然醒的惬意生活,我总是想着可能就因为这一时的懒惰,一切都不同了。
所以,我非常谨小慎微,以至于有时会陷入自我纠结中,像是强迫症那样。
如今想来,这些都是不应该的,首先在心态上尽量保持一个轻松的状态,不要给自己过大的压力。
虽然考研是如此的重要,但它并不能给我们的人生下一个定论。
所以在看待这个问题上不可过于极端,把自己逼到一个退无可退的地步。
而在备考复习方面呢,好多学弟学妹们都在问我备考需要准备什么,在我看来考研大工程,里面的内容实在实在是太多了。
首先当你下定决心准备备考的时候,要根据自己的实际情况、知识准备、心理准备、学习习惯做好学习计划,学习计划要细致到每日、每周、每日都要规划好,这样就可以很好的掌握自己的学习进度,稳扎稳打步步为营。
另外,复试备考计划融合在初试复习中。
在进入复习之后,自己也可以根据自己学习情况灵活调整我们的计划。
总之,定好计划之后,一定要坚持下去。
最近我花费了一些时间,整理了我的一些考研经验供大家参考。
篇幅比较长,希望大家能够有耐心读完,文章结尾处会附上我的学习资料供大家下载。
江西理工大学数学的初试科目为:(101)思想政治理论(201)英语一(602)数学分析和(811)高等代数(自命题)参考书目为:1.《数学分析》第四版,华东师范大学编著,上、下册,高等教育出版社,201年7月。
2.《高等代数》第四版,北京大学数学系前代数小组编,王萼芳,石生明修订,高等教育出版社,2013年8月。
跟大家先说一下英语的复习吧。
学英语免不了背单词这个难关,词汇量上不去,影响的不仅是考试成绩,更是整体英语能力的提升;背单词也是学习者最感到头痛的过程,不是背完了转身就忘,就是背的单词不会用,重点单词主要是在做阅读的时候总结的,我把不认识不熟悉的单词全都挑出来写到旁边,记下来反复背直至考前,总之单词这一块贵在坚持,背单词的日程一定要坚持到考研前一天。
数学专业英语2-4

Let P denote the set of all positive integers. Then P is itself an inductive set because (a) it contains 1, and (b) it contains x+1 whenever it contains x. Since the members of P belong to every inductive set, we refer to P as the smallest inductive set. 用P表示所有正整数的集合。那么P本身是一个归纳 集,因为其中含1,满足(a);只要包含x就包含x+1, 满足(b)。由于P中的元素属于每一个归纳集,因此P 是最小的归纳集。
Quotients of integers a/b (where b≠0) are called rational numbers. The set of rational numbers, denoted by Q, contains Z as a subset. The reader should realize that all the field axioms and the order axioms are satisfied by Q. For this reason, we say that the set of rational numbers is an ordered field. Real numbers that are not in Q are called irrational. 整数a与b的商被叫做有理数,有理数集用Q表示,Z 是Q的子集。读者应该认识到Q满足所有的域公理和 序公理。因此说有理数集是一个有序的域。不是有 理数的实数被称为无理数。
数学专业英语【第二版】(吴炯圻)

数学专业英语【第二版】1- A 什么是数学数学来自于人的社会实践,例如,工业和农业生产、商业活动、军事行动和科研工作。
与数学反过来,为实践服务和所有字段中的伟大作用。
没有现代的科学和技术分支机构可以定期制定中的数学,应用无早有需要的人来了数字和形式的概念。
然后,开发出的几何土地和三角测量的问题来自测量的问题。
若要对付一些更复杂的实际问题,男子成立,然后解决方程未知号码,因此代数发生。
17 世纪前, 男子向自己限于小学数学,即几何、三角和代数,只有常量被认为在其中。
17 世纪产业的快速发展促进了经济和技术的进展和所需变量的数量、处理从常量到带来两个分支的数学-解析几何和微积分,属于高等数学,现在有很多分支机构,其中有数学分析、高等代数、微分方程的高等数学中的可变数量的飞跃函数理论等。
数学家研究理念和主张。
所有命题公理、假设、定义和定理都。
符号是一种特殊和功能强大的数学工具,用于表示很多时候的理念和主张。
公式、数字和图表是阿拉伯数字1,2,3,4,5,6,7,8,9,0 与另外的符号"+"、减法"-",乘"*",除"\"和平等"="。
数学中的结论得到主要由逻辑推理和计算。
长期的数学史上,以中心地点的数学方法被占领逻辑扣除。
现在,由于电子计算机是迅速发展和广泛应用,计算的作用变得越来越多重要。
在我们这个时代计算不只用于处理大量的信息和数据,而且还进行一些只是可以做的工作较早前的逻辑推理,例如,大部分的几何定理的证明。
1--B 方程方程是平等的语句的两个相等的数字或数字符号之间。
因此(a-5)= 一5a 和x 3 = 5 是方程。
方程的两种——身份和方程的条件。
方程的算术或代数的身份。
这种方程中两名成员是相似的或成为相似的指示操作的性能。
因此12-2=2+8,(m+n)(m-n) = m n 是身份。
1—c 比与测量今天的思想沟通往往根据编号和数量的比较。
江西理工大学英语词汇题精选全文完整版

可编辑修改精选全文完整版江西理工大学英语词汇题 The pony was revised in January 2021U n i t11. When making modern cameras, people began to _______ plastics for metal.A. surroundB. substanceC. stretchD. substitute2. People who have difficulty when communicating face-to-face can become______ and courteous when online.A. eloquentB. elusiveC. elegantD. elaborate3. The government is putting through some ______ social reforms to improve its image.A. rationalB. recreationalC. radicalD. recurrent4. He _______ to study harder in the future so that he could have more opportunities to find a better job.A. resolvedB. resortedC. requestedD. reserved5. He proved himself a ________ successor to the former Prime Minister.A. worthwhileB. worthlessC. worthyD. worth6. Anthony is a very ________ person and never wastes anything.A. miserlyB. thriftyC. economicD. conservative7. The ghostly presence was just a (n)_________ sensation of some people.A. objectiveB. subjunctiveC. subjectiveD. ejective8. The heavy traffic ______ us for half an hour.A. maintainedB. obtainedC. retainedD. detained9. I hope I can learn more from my role model and _____ more experience.A. accumulateB. stimulateC. simulateD. formulate10. He was caught ______ when the judge produced the evidence against him.A. off-limitB. off-siteC. off-sideD. off-balance11. The company is on the verge of bankruptcy, and thousands of jobs are at ________.A. dangerB. lossC. threatD. stake12. You should ______ all the information needed for your application.A. seizeB. acquireC. captureD. snatch13. We cannot trust him anymore because he often ________ his duty.A. owesB. spoilsC. desertsD. neglects14. After a slow start, the plan soon took ______and was accepted by all.A. upB. offC. overD. away15. What she achieved in her research might _______ what she had been expecting.A. exceedB. exclaimC. excessD. extendKey: 1-5 DACAC 6-10 BCDAD 11-15 DCDBAUnit 31.The government used their emergency powers to ________ the truth about theaccident.A. suppressB. manipulateC. controlD. utilize2. He always has a lot of _______ ideas in his mind, and sometimes we do not even know what he is thinking about.A. fickleB. abnormalC. weirdD. errant3. In order to write his paper, he borrowed a lot of _______ books from the school library.A. sampleB. referenceC. resourceD. assist4. When he caught a _______ of his girl-friend in the rain, Jack asked thetaxi driver to stop to pick her up.A. glanceB. peepC. glareD. glimpse5. Embroidery calls for great care. There must not be even a single______stitch.A. recklessB. slackC. sloppyD. floppy6. This nation is noted for its economic _______.A. steadinessB. stabilityC. staticD. stationary7. Citizens have the right to know and to ______ government.A. monitorB. interfereC. controlD. supervise8. Mr. Smith asked his secretary to ________ a new paragraph in the annual report she was typing.A. injectB. installC. invadeD. insert9. It may be necessary to stop ________ in the learning process and go back to the difficult points in the lessons.A. at largeB. at intervalsC. at randomD. at length10. ________ quantities of water are being used nowadays with the rapid development of industry and agriculture.A. ExcessiveB. ExtensiveC. EffusiveD. Exclusive11. ________ recent developments we do not think your scheme is practical.A. In view ofB. In favor ofC. In case ofD. In honor of12. When you buy the spare parts for your car, try to get the _______ ones from the authorized dealer.A. genuineB. originalC. rawD. veritable13. Works of taste can ______ the mind.A. confineB. defineC. refineD. fine14. I hoped this film would provoke audiences to ______ what we could do tothe poor.A. templateB. contemptC. contemplateD. tempt15. He is ______ in his control of expenditureA. severeB. rigorous D. rigid D. graveKeys: 1-5 ACBDC 6-10 BDDBA 11-15 AACCBUnit51.They are trying to ________ the waste discharged by the factory for profit.A. exposeB. expireC. expandD. exploit2.The continuous rain ________ the harvesting of the wheat crop by two weeks.A. set backB. set offC. set outD. set aside3. Too much stress can ________ toll on your body and affect your productivity.A. giveB. takeC. haveD. make4. To my teacher I ________ this dictionary in token of affection and gratitude.A. dedicateB. delicateC. dictateD. duplicate5. As a footballer, if you're ________ to injury it can mean the end of your career.A. sensitiveB. likely B. immune D. prone6. Research universities have to keep up with the latest computer and scientific hardware ________ price.A) on account of B) regardless of C) in light of D) in accordance with7. You will not be ________ about your food in time of great hunger.A. specialB. particularC. peculiarD. specific8. We should concentrate on sharply reducing interest rates to pull the economy out of ________.A. concessionB. confessionC. sessionD. recession9. This ticket you to a free boat tour on the lake.A. entitlesB. appointsC. grantsD. credits10. This mobile app has enabled people to make connections and virtual friendships can ________ into real-life relationships.A. resolveB. revolveC. evolveD. convolve11. In the sentence “The newly ______ network culture provides opportunities as well as challenges to the traditional college English teaching”, which of the following is the odd one out?A. risingB. arisingC. poppingD. emerging12. He was proud of being chosen to participate in the game and he ________ us that he would try as hard as possible.A. insuredB. assuredC. reassuredD. secured13. If people feel hopeless, they don’t bother to ________ the skills they need to succeed.A. adoptB. acquireC. accumulateD. assemble14. We have planned an exciting publicity ________ with our advertisers.A. struggleB. campaignC. battleD. conflict15. John doesn’t believe in ________ medicine; he has some remedies of his own.A. standardB. regularC. routineD. conventionalKeys:1-5 DABAD 6-10 BBDAC 11-15 CBBBDUnit71.Techniques for ________ sleep would involve learning to control both mindand body so that sleep can occur.A.promotingB. strengtheningC. cultivatingD. simulating2.Our ________ reaction when someone causes us pain is to strike backA.intuitiveB. instinctiveC. talentedD. natural3.They were ________ admission to the military exhibition because they wereforeigners.A. deniedB. declinedC. deprivedD. rejected4. Residents were cutting their lawns, washing their cars and otherwise________ a pleasant, sunny day.A. idling awayB. wasting awayC. chasing awayD. driving away5. We’d like to ________ a table for five for dinner this evening.A. preserveB. conserveC. reserveD. deserve6. The European Union countries were once worried that they would not have________ supplies of petroleum.A. proficientB. efficientC. deficient D) sufficient7. As Jane was about to graduate, she was in a _______ whether to continue her website or seek work.A. difficultyB. troubleC. adversityD. dilemma8. Several witnesses can ________ to her good character.A. proveB. confirmC. attestD. testify9. Now, I'm still _______, but I'm much more open to spending on things that enrich my life.A. frugalB. extravagantC. stingyD. economic10. The group is accused of_________ its members to commit crimesA. luringB. persuadingC. temptingD. brainwashing11. The work was almost complete when we received orders to ________ nofurther with it.A. progressB. proceedC. promptD. promote12. A dark suit is ________to a light one for evening wear.A. favorableB. suitableC. preferableD. adorable13. It was in the United States that I made the ________of Professor Jones.A. acknowledgementB. acquaintanceC. recognitionD. association14. Mr. Smith was the only witness who said that the fire was ________.A. artificialB. deliberateC. well-intentionedD. innocent15. There was a big hole in the road which ________ the traffic.A. set backB. lay backC. held upD. kept downKeys: 1-5 ABAAC 6-10 DDCAD 11-15 BCBBC。
数学专业英语2-2

The line is named by labeling two points on it with capital letters or one small letter near it. The straight line extends infinitely far in two directions and has no ends. The part of the line between two points on the line is termed a line segment.
我们都熟悉直线,但是很难定义直线。可能可以用移动一支铅 笔或者钢笔横穿一张纸留下的痕迹来描述直线。
直线可以被看做是一维的,即只有长度。尽管我们画一条直线 的时候会赋予它宽度和厚度,但是当考虑直线的时候,只考虑 痕迹的长度。
A point has no length, no width, and no thickness, but marks a position. We are familiar with such expressions as pencil point and needle point. We represent a point by a small dot and name it by a capital letter printed beside it, as “point A” in Fig. 2-2-1.
有三种线:直线,折线和曲线。曲线是指其中没有任何部分是 直的。折线是由连起来的直线段构成,如图2-2-3中的ABCDE.
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一、数学符号翻译12/156 twelve over one hundred and fifty-six234/567 two hundred and thirty -four over five hundred and sixty-seven 4% four percent7‰ seven permill6.79 six point seven nine 52.3 three point two five recurring85xthe eighth root of x to the fifth power 53x x to the minus three fifthsdx x f ba )( f is integrable on [a,b]32)(dx x f f is integrable on [2,3]x f the partial (derivative) of f with respect to x yf the partial (derivative) of f with respect to y 5log 3 the logarithm of five to the base threex a log the logarithm of x to the base aB A A cap B / A meet B / A intersection BB A A cup B / A join B / A union BA a a is an element of AB b b is an element of B二、名词翻译function theory 函数论 schematic representation 图解表示 geometry 几何学 trigonometry 三角学consequence 推论 proposition 命题theorem 定理 pyramid 棱锥cone 圆锥 abscissa 横坐标ordinate 纵坐标 coordinate system 坐标系 coordinate axis 坐标轴 polygonal region 多边形区域 tangent 切线 slope 斜率complex-valued sequence 复值序列 convergence 收敛real valued sequence 实值序列 divergence 发散rational number 有理数 irrational number 无理数 odd number 奇数 even number 偶数prime 质数、素数 composite 合数plane 平面 surface 曲面broken line 折线 Venn diagram 文氏图universal set 全集 the underlying set 基础集 proper subset 真子集 quadratic equation 二次方程 the absolute-value function 绝对值函数parabolic segment 抛物弓形三、中译英(1)17世纪之前,人类局限于初等数学,即几何,三角学和代数,那时只考虑常数。
Before 17th century, man confined himself to the elementary mathematics, i.e., geometry, trigonometry and algebra, inwhich only the constants were considered.(2)两个整数的和、差或积是一个整数,但是两个整数的商未必是一个整数。
The sum, difference, or product of two integers is an integ er, but the quotient of two integers need not be an integer.(3)设X是线性空间V中k个元素组成的一个线性无关集合,L(X)是由X张成的子空间。
那么,L(X)的每一个元素都可以表示成X的元素的线性组合。
Let X be an independent set consisting of k elements in a linear space V and let L(X)be the subspace spanned by X, then each element of L(X) can be expressed as a linear combination of element of X.(4)若P(A)>P(B),则称事件A比事件B有更大的可能性;如果P(A) P(B),则称事件A至少和事件B的可能性一样大。
The event A is called more likely than B if P(A)>P(B), and at least as likely as B if P(A) P(B).(5)微分方程的研究直接受到力学、天文学和数学物理的推动。
The study of differential equations has been directly inspired by mechanics, astronomy, and mathematical physics.(6)由定义导数的过程所提供的几何解释以一种自然的方式导出了关于曲线的切线的思想。
The procedure used to define the derivative has a geometric interpretation which leads in a natural way to the idea of a tangent line to a curve. (7)一个复值序列收敛当且仅当它的实部和虚部分别收敛。
A complex-valued sequence converges if and only if both the real part and the imaginary part converge separately.(8)几何主要不是研究数,而是形,例如三角形,平行四边形和圆,虽然它也与数有关。
Geometry mainly studies not numbers but figures such as triangles, parallelograms and circles, though it is related with numbers.四、英译汉1、Two events are said to be mutually exclusive when both cannot happen at the same time.If E denotes an event,then the event that E does not happen is called the complementary event of E,and is denoted by E .Obviously,E and E are mutually exclusive.Since an event either happens or does not happen,the sum of their probabilities is 1.两个事件若它们不能在同一时间都发生时我们称这两个事件是互斥的。
如果E 表示一个事件,然后 E 不会发生的事件称为 E的补充性事件,并由表示E 。
很明显,E 和E 是互斥的。
因为对于事件发生或不发生,其概率的总和是 1。
2、Thus p q is true if both p and q are true or if both p and q arefalse.The following are English-language equivalents to p q : “ p if and only if q ”,”p is a necessary and sufficient condition for q.”and “p precisely if q.”It is worth emphasizing that the compound proposition p q and its converse q p are quire different;they have different truth tables.因此 p q 是真的,在 p 和 q 同时为真或 同时为假时成立。
以下是英语语言描述,等同于p q : "p 当且仅当 q","p 是 q 的必要和充分条件"和"p 准确如果 q."值得强调的是复合命题 p q 和它的逆命题 q p 是不同的,他们有不同的真值表。
3、We now introduce a natural generalization of partial derivatives.In the definition of ),(001y x f ,the numerator of the difference quotient used involves the value of ),(y x f at two points ),x (00y x and ),(00y x .As x approaches zero,the first point approaches the latter along the line y=0y .For ),(002y x f a point ),(00y y x approaches ),(00y x along the line x=0x .We now replace these two special lines by an arbitrary line through ),(00y x .我们现在介绍的偏导数的自然推广。
由),(001y x f 中的定义,所使用的差商的分子涉及),(y x f 在),x (00y x 和),(00y x 两个点的值。
当x 接近零,第一点沿直线y =0y 接近后者。
对于),(002y x f 点),(00y y x 沿直线x =0x 趋向),(00y x 。
现在我们通过一个任意经过点),(00y x 的线来更换这两个特殊的线。
4、The whole numbers have many important subsets.A whole number is said to be even if it is divisible by 2;2,6 and 18 are example of even numbers.A whole number is said to be odd if it is not divisible by 2;1,7and 13 are examples of odd numbers.The natural numbers greater than 1 and called prime or composite.A number is prime if it is divisible only by 1 and itself.A number is composite if it is divisible by a natural number other than 1 and itself.整数集有很多重要子集。