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趣味数学小故事大全我曾听到有人说我是数学的反对者，是数学的敌人，但没有人比我更尊重数学，因为它完成了我不曾得到其成就的业绩——哥德。
今天小编在这给大家整理了数学小故事大全，接下来随着小编一起来看看吧!数学小故事(一)1.巧测金字塔高度金字塔是埃及的著名建筑，尤其胡夫金字塔最为著名，整个金字塔共用了230万块石头，10万奴隶花了30年的时间才建成这个建筑。
金字塔建成后，国王又提出一个问题，金字塔倒底有多高，对这个问题谁也回答不上来。
国王大怒，把回答不上来的学者们都扔进了尼罗河。
当国王又要杀害一个学者崐的时候，著名学者塔利斯出现了，他喝令刽子手们住手。
国王说：“难道你能知道金字塔的高度吗?”塔利斯说：“是的，陛下。
”国王说：“那么它高多少?”塔利斯沉着地回答说：“147米。
”国王问：“你不要信口胡说，你是怎么测出来的?”塔利斯说：“我可以明天表演给你看。
”第二天，天气晴朗，塔利斯只带了一根棍子来到金字塔下，国王冷笑着说：“你就想用这根破棍子骗我吗?你今天要是测不出来，那么你也将要被扔进尼罗河!”塔利斯不慌不忙地回答：“如果我测不出来，陛下再把我扔进尼罗河也为时不晚。
”接着，塔利斯便开始测量起来，最后，国王也不得不服他的测量是有道理的。
小朋友，你知道塔利斯是如何进行测量的吗? 2. 蜗牛何时爬上井?一只蜗牛不小心掉进了一口枯井里。
它趴在井底哭了起来。
一只癞蛤蟆爬过来，瓮声瓮气的对蜗牛说：“别哭了，小兄弟!哭也没用，这井壁太高了，掉到这里就只能在这生活了。
我已经在这里过了多年了，很久没有看到过太阳，就更别提想吃天鹅肉了!”蜗牛望着又老又丑的癞蛤蟆，心里想：“井外的世界多美呀，我决不能像它那样生活在又黑又冷的井底里!”蜗牛对癞蛤蟆说：“癞大叔，我不能生活在这里，我一定要爬上去!请问这口井有多深?”“哈哈哈……，真是笑话!这井有10米深，你小小的年纪，又背负着这么重的壳，怎么能爬上去呢?”“我不怕苦、不怕累，每天爬一段，总能爬出去!”第二天，蜗牛吃得饱饱的，喝足了水，就开始顺着井壁往上爬了。
英美法系重视程序的名言every law has no atom of stregth, as far as no public opinion supports it. (wendell phillips, american leader against slavery)若是没有公众舆论的支持，法律是丝毫没有力量的。
(美国废奴运动领袖菲力普斯 w)good order is the foundation of all things. (e.burke, btritish statesman)良好的秩序是一切的基础。
(英国政治家伯克 e)guilt always hurries towards its complement, punishment; only there doesits satisfaction lie. (lawence durrell, british writer)犯罪总是以惩罚相补偿;只有处罚才能使犯罪得到偿还。
(英国作家达雷尔 l)i disapprove of what you say, but i will defend to the death your right to say it. (voltaire, frech writer)我不同意你说的话，但是我愿意誓死捍卫你说话的权利。
(法国作家伏尔泰)if there were no bad people, there would be no good lawyers. (charles dickens, british novelist)倘若世上没有坏人，也就不会有好的律师。
(英国小说家狄更斯 c)if we only had some god in the countrys laws, instead of beng in such a sweat to get him into the constitution, it would be better all around. (mark twain, american writer)如果我们国家的法律中只有某种神灵，而不是殚精竭虑将神灵揉进宪法，总体上来说，法律就会更好。
英语墨菲定律金句-回复以下是关于“墨菲定律金句”的英文文章，文章长度为1747字。
Murphy's Law: Expect the UnexpectedIntroductionMurphy's Law is a well-known adage that states, "Anything that can go wrong will go wrong." Named after Edward A. Murphy, an American aerospace engineer, this law emphasizes our instinctive ability to foresee pessimistic outcomes or prepare for unforeseen events in our lives. In this article, we will explore the origins of Murphy's Law, discuss its relevance in various aspects of our lives, and provide tips on how to handle unexpected situations when they arise.Origins of Murphy's LawEdward A. Murphy first proposed Murphy's Law in the late 1940s while working on an experiment involving G-forces and human acceleration tolerance. During the experiment, a technician incorrectly wired the sensors, resulting in a failed measurement.Frustrated with the error, Murphy exclaimed, "If there's any way to do it wrong, he'll find it!" This incident led Murphy to formulate his famous law, which was later popularized by members of the aerospace industry. It eventually gained wider recognition and became an integral part of popular culture.Relevance of Murphy's LawMurphy's Law is applicable to numerous aspects of our lives, including personal, professional, and everyday situations. It reminds us to expect the unexpected and prepare for potential setbacks. For instance, in personal relationships, unforeseen arguments or misunderstandings can arise even when we least expect them. By accepting the inevitability of such situations, we can better equip ourselves to handle conflicts and maintain healthy relationships. Similarly, in the professional world, deadlines may be missed, projects may face unexpected obstacles, and colleagues may fall ill. Adhering to Murphy's Law helps us remain calm and adapt to changing circumstances, ensuring that we are ready to tackle any challenges that come our way.Handling Unexpected SituationsWhen unexpected situations occur, it is crucial to approach them with a calm and composed mindset. Here are some steps to help you effectively handle the unexpected:1. AcceptanceThe first step in dealing with unexpected situations is accepting that they happen. Resistance and denial will only amplify stress and anxiety. By acknowledging that setbacks are a part of life, we can redirect our focus towards finding practical solutions.2. Assess the SituationOnce you have accepted the reality of the unexpected, it is essential to assess the situation objectively. Evaluate the impact of the situation, gauge its severity, and determine the best course of action. Prioritize tasks and allocate resources wisely to minimize further complications.3. AdaptabilityFlexibility and adaptability are key qualities in dealing with unexpected situations. Embrace the change, quickly adjust your plans, and explore alternative strategies. By being open to new ideas and approaches, you can turn unexpected challenges into opportunities for growth and innovation.4. Seek SupportDuring challenging times, seeking support from friends, family, or colleagues can provide perspective and assistance. Discussing the situation with someone you trust can help alleviate stress and generate fresh insights. Remember, you are not alone, and reaching out for support is a sign of strength, not weakness.5. Learn from the ExperienceEvery unexpected situation offers valuable lessons. Reflect on the event once it has passed, analyzing what went wrong and identifying areas for improvement. Use this knowledge to grow and develop strategies for preventing similar occurrences in the future.ConclusionMurphy's Law serves as a reminder that life is full of uncertainties, and unexpected situations are bound to arise. By embracing the principle of expecting the unexpected, we can better prepare ourselves mentally and emotionally for obstacles that come our way. The ability to handle unexpected situations calmly and effectively is a vital skill for personal and professional success. So, let us keep Murphy's Law in mind and face life's challengeshead-on, knowing that even in the face of uncertainty, we have the power to persevere and thrive.。
1.That sex ratio will be favored which maximizes the number ofdesendants an individual will have and hence the number of gene copies transmitted2.hardy’s weakness derived from his appreant inability tocontrol the comings and goings of these divergent impluses and from his unwillingness to cultivate and sustain the energentic and risk ones.3.virginia Woolf’s provocative statement about her intentions inwriting Mrs.Dalloway has regularly been ignored by the critics, since it highlights an aspect of her concerned with examing states of traditional picture of the “poetic” novelist intricate pathways of individual consciousness.4.5.6.7.8.This preference for exogamy ,Gutman suggests, may havederive from WestAfrican rules govening marriage,which , though they differed from one tribal group to another, all invovles some kind of prohibition against unions with close kin.9.his thesis works relatively well when applied to discriminationagainst Blacks in the US,but his definition of racial prejudice as “racially-based negative prejudgments against a group generally accepted as a race in any given region of ethnic competition ,”can be interpreted as also including hostility toward such ethnic groups such as the Chineses and the Jews in medieval Europe.10.s uch variations in size,shape,chemistry,conductionspeed,exciation threshold ,and the like as had been demostrated in nerve cells remained negligible in significance for any possible correlation with the maniford dimensions of mental experience .11.i t was possible to demonstrated by other methods refinedstructural differences among neuron types;however,proof was lacking that the quality of the impluse or its condition was influenced by these differences,which seemed instead to influence the developmental patterning of the nueron circuits.12.a lthough qualitative variance among nerve was never rigidlydisproved,the doctrine was generally abandoned in favor of the opposing view ,namely,that nerve impluses are essantially homogeneous in quality and are transmitted as “common currency “throughout the nervous system.\13.o ther experiments reavealed slight varitions in thesizes ,number,arrangment ,and interconnection of the nerve cells,but as far as psycho neural correlations were concerned ,the obvious similarities of these sensory field to each other seemed much remarkable than any of the minute differences.14.a lthough some experiments show that,as an object becomesfamiliar ,its internal representation becomes more holistic and the recognition process correspondingly more parallel,the weight of evidence seems to support the serial hypothesis ,at least for objects that are not notable simple and familiar. 15.i n large part as a consequece of feministmovement ,historians have focused a great deal of attention in recent years on determining more accurately the status of women in various periods.16.i f one begins by examining why ancients refer to Amazons , itbecomes clear that ancient Greak descriptions of such societies were meant not so much to respresent observed historical fact-real Amazonian societies-but rather to offer “moral lessons”on the supposed outcome of women’s rule in their own society.17.t hus ,for instance ,it may come as a shock to mathmaticiansto learn that the Schrodinger equation for the hydrogen atomis not a literally correct description of this atom ,but only an approximation to a somewhat more more correct equation taking account of spin ,magnetic dipole ,and relativistic effects;and that this corrected equation is itself only an imperfect approximation to an infinite set of quantum field-theoretical equations.18.t he physicist rightly dreads precise argument ,since anargument that is convicing only if it is precise loses all its force if the assumptions on which it is based are slightly changed,whereas an argument that is convicing though imprecise may well be stable under small perturbations of its underlying assumptions.19.h owever ,as they gained cohession ,the Bluestockings cameto regard themselves as a women’s group and to possess a sense of female solidarity .lacking in the salonnieres, who remained isolated from one another by primacy each held in her own salon .20.a s my own studies have advances,I have been increasinglyimpressed with the functional similiarties between insect and vertebrate and less so with the structual differences that seem ,at first glance,to consititute such an immense gulf between them.21.A lthough fiction assuredly springs from politicalcircumstance,its authors react to those circumstances in ways other than ideological ,and talking about novels and stories primarily as instruments of ideology circumvents much of the fictional enterprise.22.i s this a defect ,or are the authors working out of ,or trying toforge ,a different kind of aesthetic?23.i n addition , the style of some Black J,verges onexpressionism or surrealism ;does this tchnique provide a counterpoint to the prevalent theme this at portrays the fate against which Black heroes are pitted ,a theme usually conveyed by more natualistic modes of expression?24.B lack Fiction surveys a wide variety of novels ,bringing to ourattention in the process some fascinating and little-known works likes James Weldon Johnson’s Autobiography of an EX-colored Man.25.A lthough these molecules allow radiation at visiblewavelengths , where most of the energy of sunlight is concentrated , to pass through ,they absorb some of the26.27.28.29.30.31.i n the periods of zooplankton abundance ,that is ,in the latespring and in the summer, Haney recorded maximum daily community grazing rates, for nutrien-poor lakes and bog lakes ,respectively ,of 6.6percent and 114 percent of daily phytopianktan production .32.T he hydrologic cycle, a major topic in this science,is thecomplete cycle of phenomenna through which water passes,beginning as atomspheric water vapor ,passing into liquid and solid form as precipitation ,thence along and into the ground surface,and finally again returning to the form of atomspheric water vapor by means of evaporation and transporation.33.O nly when a system possesses natual or artficial bounderiesthat associate the water within it the phyrologic cycle may the entire system properly be termed hydrogeologic.34.T he historian Fwrote in 1890’s that the agrarian discontentthat had been developing steadily in the US since about 1870 had been precipitated by the closing of the internal frontier –that is ,the depletion of available new land need for further expansion of the American farming system.35.I n the early 1950’s,historians who studied peindustrialEourpe began,for the first time in large numbers ,to investigate more of the population than 2or 3 percent who comprised the political and social elite:the kings ,generals,judges,nobles,bishops,and local manates who had hitherti filled history books.36.H istorian such as L have used the document to extract casehistories,which have illuminated the attitude of different social groups(the attitudes include ,but are not confined to,attitudes toward crime and law)and have revealed how the authorities adimisttered justice.37.I t can be inferred from the passage that a historian whowished to compare crime rates per thousand in a Eouropean city in one decade of the fifteenth century with crime rates in anothor decade of that century would probably be most aided by better information about which of the following？38.。
尼科尔森《微观经济理论-基本原理与扩展》（第9版）第2篇选择与需求 第3章偏好与效用课后习题详解跨考网独家整理最全经济学考研真题，经济学考研课后习题解析资料库，您可以在这里查阅历年经济学考研真题，经济学考研课后习题，经济学考研参考书等内容，更有跨考考研历年辅导的经济学学哥学姐的经济学考研经验，从前辈中获得的经验对初学者来说是宝贵的财富，这或许能帮你少走弯路，躲开一些陷阱。
以下内容为跨考网独家整理，如您还需更多考研资料，可选择经济学一对一在线咨询进行咨询。
1．画出下列效用函数的无差异曲线，并判断它们是否是凸状的（即边际替代率MRS 是否随着x 的增加而递减）。
（1）(),3U x y x y =+ （2）(),U x y x y =⋅ （3）(),U x y x y =+ （4）()22,U x y x y =- （5）(),xyU x y x y=+ 答：（1）无差异曲线如图3-7所示，为一组直线。
边际替代率为：/3/13x y MRS f f ===，为一常数，因而无差异曲线不是凸状的。
图3-7 完全替代型的无差异曲线（2）无差异曲线如图3-8所示，为性状良好的无差异曲线。
边际替代率为：()()0.50.50.5///0.5/x y y x MRS f f y x y x -===，随着x 的递增，MRS 将递减，因而有凸的无差异曲线。
图3-8 凸状的无差异曲线（3）无差异曲线如图3-9所示。
边际替代率为：0.5/0.5x y MRS f f x -==，因而边际替代率递减，无差异曲线是凸状的，此为拟线性偏好的效用函数。
图3-9 拟线性型的无差异曲线（4）无差异曲线如图3-10所示。
边际替代率为：()0.522220.5/0.52/0.5()2/x y MRS f f x y x x y y x y --==-⋅-⋅=，因而边际替代率递增，无差异曲线不是凸状的。
图3-10 凹状的无差异曲线（5）无差异曲线如图3-11所示。
无条件的最优货币政策Tatiana Damjanovic, Vladislav Damjanovic and Charles Nolan School of Economics and Finance, University of St. Andrews, Castlecliffe, The Scores, St. Andrews, Fife KY16 9AL, Scotland, UK; Received 2 January 2007; revised 9 January 2008; accepted 10 January 2008. Available online 19 January 2008.摘要:我们建立了一个简单而直观的方法来推导解析无条件的最优货币政策，即分析一种持久性利益最优货币政策。
这个方法可以用广义非线性二次问题和潜在非线性问题来研究。
我们将以规范的新凯恩斯主义的框架为例来说明这种方法。
关键词:无条件的预期，最优货币政策引言在这篇文章中我们采用泰勒(1979年)的说法，他认为在合理的预期条件下，采用货币政策，“平均”是最优解。
也就是说，泰勒认为对于一个给定的经济模型，包括随时间变化的潜在可能受冲击的财产信息和理性预期，那么最优货币政策是优化的预期目标函数的最佳解。
这种对政策评估的方法已经采用了许多次；例如，Rotemberg and Woodford （1998），Woodford (1999), Clarida 等(1999), Erceg等(2000),Kollmann (2002) 和Schmitt-Grohe 及Uribe (2007)，不一一例举。
最近，Blake (2001)、Jensen和McCallum(2002)和Jensen和McCallum (2006)提出一个程序，可以确定基于优化的无条件的价值目标函数的最适货币政策。
然而，这些分析是采用数值方法来恢复无条件的最优货币政策的。
墨菲定律的翻译(2007-03-21 00:37:52)Murphy's Law墨菲定律1. Anything that can go wrong will go wrong.如果有可能出错的事情准会出错。
(不要心存侥幸之心！)2. You will always find something in the last place you look.你总是在最后一个地方找到你遗失的东西。
(做事要细心，不要粗心大意。
)3. No matter how long or how hard you shop for an item, after you've bought it, it will be on sale somewhere cheaper.不管你花了多少时间和精力去买一样东西，买来后你总是会发现某处卖得更便宜。
（不要以为自己能占到或是捡便宜。
）4. The other line always moves faster.另外一条队伍总是移动得快一些。
(人外有人，山外有山。
或是：做一行怨一行。
)5. In order to get a loan, you must first prove you don't need it.为了申请到贷款，你首先得证明你不需要它。
（银行只有锦绣上添花，没有雪中送炭。
）6. Anything you try to fix will take longer and cost you more than you thought.不管修理什么东西，都会花掉比你预计的要多的时间和金钱。
（要做就一次做好！）7. If you fool around with a thing for very long you will screw it up.如果长期懒散地对待一件事情，你会把它弄得一团糟。
(要做就得速战速决！)8. If it jams force it. If it breaks, it needed replacing anyway.如果它堵住了就使劲压。
mayer小波公式
Mayer小波公式是一个经典的数学公式，用于描述函数的多项式逼近性质。
该公式由奥地利数学家Joseph Mayer于1912年提出，是数学分析中的重要工具之一。
Mayer小波公式的表述如下：设$f(x)$是一个定义在区间$[a,b]$上的函数，$p(x)$是一个$n$次多项式，则有：
$$int_a^b |f(x) - p(x)|^2 dx = int_a^b |f(x)|^2 dx - sum_{k=0}^{n-1} lambda_k^2 |hat{f}(k)|^2$$
其中，$hat{f}(k)$表示$f(x)$的$k$次Fourier系数，$lambda_k$是一个常数，它满足：
$$sum_{k=0}^{n-1} lambda_k^2 = int_a^b |P_n(x)|^2 dx$$ 其中$P_n(x)$是$n$次Legendre多项式。
Mayer小波公式的意义在于，它揭示了函数的平方误差与逼近多项式的系数之间的关系。
具体来说，右边的第一项是函数
$f(x)$的平方$L^2$范数，右边的第二项是多项式$p(x)$在$L^2$意义下与$f(x)$的差的平方$L^2$范数。
公式的左边则是它们之间的差的平方$L^2$范数，也就是误差的平方$L^2$范数。
这种平方误差与平方范数之间的关系，使得该公式在函数逼近和信号处理等领域具有广泛的应用。
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