大一有机化学第十三题，求过程及答案谢谢。

when i was a freshman i have already heard about you

lim(x→0) [f(x)/g(x)]
=lim(x→0) [(1-e^x)/(1-cosx)]
=lim(x→0) [(-e^x)/(sinx)]→∞
∴f(x)是g(x)的低阶无穷小,选B

这个方程可看作X关于y的函数（x是y的函数）,关于x的一阶线性非齐次微分方程,可利用公式（在课本上给y是x的函数的公式为y=e^-∫P(x)dx(∫Q(x)e^∫P(x)dx+C））
你可参考

有区别.你说的“f(x)在x趋近于a的空心领域里有界”中f(x)有界的前提为x趋近于a的空心领域里,若x不趋于a,则f(x)未必有界,这点可用函数极限的局部有界性定理来解释,可用语言序数为某一有极限函数f(x)仅在一个小范围内(...

和圆周有关,大轮转一圈可以带动小轮转一圈以上,这样就可以提高功的效率.如果调换过来,小轮转好几周才能让大轮转满一圈.根据圆的角度,即360度,不困大轮还是小轮,都要蹬一个圆的角度,才能使圆转一圈.

x+2y=16 0

I have a dream that one day I can be living in a castle forever.It might sound a bit like a noble in a novel but it's still realistic.I don't want to go to work at all.I like to stay with my loved one all the time.I will plant lots of grapes in the back yard and make wine.What would you expect more than a country life of having a woman,castle,and wine.However,it's an expensive dream.I'd have to work damn hard to afford a castle somewhere and a vineyard.And it's a distant future from now because my loved one haven't yet even come to my life.But I will work hard on it.

1.
设|bn|0,存在N,当n>N时,|an|N时,|anbn|

令x+1=t^3,0

Dear Miss Wang,
This is Ivy from English Class One. I am writing to thank you for your guidance and patience in our English class. I am not good at English, especially in speaking and listening. A...

my name is .i am an .university year one student.i like dancing,tennis.i don't like english but i will learn.

嗯,刚开始就这样了,估计你上课也走神了.
课前的预习和课后的补习很重要,课堂上你可以不听,但课下一定要弄懂.其实把例题搞懂你已经学到七七八八了.
加油吧,刚开始,别气馁.持之以恒才对

（Ⅰ）甲班高等数学成绩集中于60分-90分之间，而乙班数学成绩集中于80-100分之间，
所以乙班的平均分高．-----（3分）
（Ⅱ）记成绩为86分的同学为A，B其他不低于80分的同学为 C、D、E、F，
“从甲班高等数学成绩不得低于80分的同学中随机抽取两名同学”的一切可能结果组成的基本事件有：
（A，B）、（A，C）、（A，D）、（A，E）、（A，F）、（B，C）、（B，D）、（B，E）、（B，F）、
（C，D）、（C，E）、（C，F）、（D，E）、（D，F）、（E，F），一共15个，
“抽到至少有一个86分的同学”所组成的基本事件有：
（A，B）、（A，C）、（A，D）、（A，E）、（A，F）、（B，C）、（B，D）、（B，E）、（B，F）
共9个，------（5分）
故 所求事件的概率为 P=[9/15]=[3/5]．-----（7分）

甲班 乙班 合计
优秀 3 10 13
不优秀 17 10 27
合计 20 20 40---------（9分）
（Ⅲ）K²=
4×(3×10×−10×17)2
13×27×20×20≈5.584＞5.024，因此在犯错误的概率不超过0.025的前提下，
可以认为成绩优秀与教学方式有关．------（12分）

两边取定积分,【-1,1】,看清楚是定积分,不是求导,别搞混了、

三个女生的话……就以友情为主题可好?《美人鱼（ Aquamarine）》,我记得末尾有一段时升华人鱼与两个人类少女的友情的,建议你们自己先看一遍再定夺.迪士尼电影《小叮当》也是几个小精灵的冒险,个人觉得也很适合,当然具体操作还得看你们.

My favourite teacher is Mr Zhang.I think he is one of the best teachers in my school.He is more than thirty years old and he is tall and strong.He teaches us English.He speaks English very well.He has taught English for more than ten years.He always teaches us patiently.He always praises and encourages us when we finish a role in a play or a dialogue.His words are very important for us and give us confidence and courage.He gives us what we need,so we are grateful.He is very kind to us and he is also very strict with us in our studies.In my eyes,he is not only an English teacher,but also a good friend.I often tell him something about my thoughts.
He likes his students to ask him questions.He often has many ways of making his classes lively and interesting,so students all like his class very much.He is one of the most popular teachers in our school.He always receives a lot of cards on Teachers' Day.But he says,“The best present for me is your hard work.”
I'm very lucky to have such a good teacher.

书店里有很多课文翻译书的

A:Excuse me.Could you please show me the way to dormitory building
B:yes,of course,walk along the road and then turn left,you will find it.
A:thank you so much !
B:IT is my pleasure !This must be your first day here,and you are a new girl here,right?
A:yeah !
B:I was in the same mood one year ago.And I knew a little about our school when i came here.But the people here are very kind ,it makes me feel better .
A;I see,And thank you again.
B:you are welcome.Good luck!
A:yeah,bye
B:bye

要多长?
我先写一篇
你再告诉我行不行
1.
A:Where do you go to school?
B:I go to XXX university.
A:Do you enjoy school life there?
B:yes,very much so.the lecturers are very informative,and the students are very friendly
A:Oh,that is nice.How is the environment there?
B:there is some nice scenery.there are lots of trees around campus,and works of art are displayed in the lecture halls.
A:what about homework?do you have a heavy workload?
B:we don't have much homework,but we have to do a lot of reading at home to catch up with what has been taught in lectures.and we also have to prepare for each tutorial.
A:I see.

我们这样看 A=√x+√a+√(x-a)
(√x-√a+√(x-a))/√(x^2-a^2)
=(√x-√a+√(x-a))*A/√(x^2-a^2)*A
=(x-a-√(x-a))/√(x-a)*√(x+a)*A
=(√(x-a) -1)/√(x+a)*A
limx->a(√x-√a+√(x-a))/√(x^2-a^2)
=-√2/4a

y = 1/(x^2 + 5x + 6) = 1/(x + 2) - 1/(x + 3)
y^(100) = 100!/(x + 2)^101 - 100!/(x + 3)^101
Mathematica:
In[24]:= D[1/(x+2)-1/(x+3),{x,100}]
Out[24]= 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000/(2+x)^101-93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000/(3+x)^101

一个强调塑,一个强调透,本来就不是一回事,学哪个以后都要从新学另外一个,水彩上手难但是以后却容易,水分相反.建筑学这样的工科学生主要通过材料了解空间表达,色彩认识,达到对目标物的迅速,准确和到位,开课目的不是学艺术,如果是美术系的,教学深度等等都会是另外一回事.我认为学生画水粉常常会很厚,如果这样还不如学习水彩.习惯厚的表达,学习水彩非但不会容易反而会很有障碍.也有学生把水彩画厚当水粉用,说不定他们以后学水粉会容易.总之,这东西学一样不就得了,如果要继续还不如学学其他的表达方法,比如丙稀什么的.

先纠正一下,摆线参数方程：x=a(t-sint)y=a(1-cost)应该是摆线一个周期的旋转体吧,t∈[0,2π],要不然就无穷大了.可以先算摆线与y=2a、x=0、x=2πa围成的柱体体积,再用外围圆柱体减掉就是了.旋转体体积计算方法课本上...

Every day we learn in the classroom, one will be able to see the rise of "hard-compliance, respecting teachers, the school loved" the school motto. However, whether or not we thought of ourselves in the end there is not really to "respect for the teaching profession," This is it? ?
Against teachers, it is easy to think of Confucius, the blind writer Helen Keller, etc., they can be called Jesus Christ, name and good willcoexistence, go down in history. And tens of thousands who work in the spirit of open country on the teachers, only because they do not have a celebrity or a great man as the magnificent achievements of their efforts and not known by the conviction on the praise. They work hard, and in the hot sun, in heavy rain, the yield of fruit are also sweet fruit acid fruit, when the community in enjoying the fruits of them, please remember them! ?
The glorious work of the great teachers, has been affirmed and accepted by people. "Village of female teachers," "Spring," "love education" and "last lesson" in the image of teachers has been etched into the hearts of people. However, the aesthetic perspective of a difference there: in a certain distance apart are better things from a closer, it is the one thing. Hence, many people are willing to engage in the profession, does not include teachers. Actually, the flowers and the gardener is zhulianbihe, solidarity, but as a result of teachers and students meet every day, a short distance, and many students of teachers not "to love each other." We are in the habit of "shibiao" standards of teachers, and teachers if not expected, as there are imaginative power, some people will be surprised and even ridicule. I think that teachers are not Superman, but also by no means inferior. As a result of the work of the teachers are real people, not drawings or machine tool life, therefore, teachers have their special work stand, I am afraid not very well understood. ?
Rostrum, the eyes of a teacher's Temple, no longer rostrum than the deprivation of the rights of teachers but also feeling sad and a shame. I am the teacher, but also will not easily give up the podium. Sick leave揣着single rostrum, not advanced in school stories, such a thing as too much. The reasons why, as a female teacher said, real simple: "I am playing a sweater, do not want to let others to play a few half-way into the needle, because everyone is different elastic gesture." This is the case, 365 a year days, regardless of heat or ice cool winter day, the thought of waiting for the class of five looking for a dozen students, teachers will always try to remove all obstacles. A rostrum, he must forget all the pain of all this, the only student in his mind at the moment. Their precious youth to dedicate the podium, in the re-diploma today, they do not have the energy nor time to enjoy the book and then group earned higher diploma, teacher's own ability and experience, the kind of professionalism more than Diploma no life! ?
Let us cherish this wonderful time and treasure to get along with teachers every day.

这个,自己写好一点,容易背……

What does friendship mean? There is no definite answer. An eternal theme in literature, friendship is also indispensable in daily life. Friendship is to our life what salt is to dasher. When you are happy, friendship is just like adding flowers on the brocade; when you are sad, friendship is a dose of consolation; if you are in trouble, friends will surround you and remove the barriers for you; if you have a hard nut to crack, you can turn to friends for help. We admire the great friendship between Marx and Engel, which firmly combined them and pushed them forward on the road to exploring and fulfilling Communism.Friendship isn't almighty, but no one can live happily withoutit.
够吗

Patient Good morning,doctor!
早上好,医生!
Doctor Morning!What's your trouble,young man?
早上好!怎么了,年轻人?
Patient I feel sick and I have a headache.
我感觉恶心,并且我头疼.
Doctor How long have you been like this?
你什么时候开始这样的呢?
Patient Since last night.
从昨晚开始.
Doctor Let me look you over carefully.
让我仔细看一看.
Patient Is anything wrong with me?
我有什么事吗?
Doctor Yes,but it's not serious.you've got the flu.Here are some pills for you.Plerse take them three times a day and drink moer water.
是的,但它并不严重.你得了流感.这是一些药丸.请一天喝三次,并多喝些水.
Patient How soon can Ibe all right again?
我多久才会好?
Doctor If you have a good rest,you will be all right in three days.
如果你好好休息,你将在三天内好的
Patient OK,thanks a lot!
好的,

法国作家雨果的旷世巨著《悲惨世界》,是他酝酿构思三十余年而创作出来的稀世珍品,被称为人类苦难的“百科全书”.这部卷帙浩繁的长篇小说,赞颂了真善美,揭露了假恶丑.这部作品是作者用三十余年的心血凝结成的,其间充...

不要用高中的学习方法来学习大学的物理.大学物理建立的基础还是高等数学,微积分,偏微分方程,量子力学等.习题是要做一些,但是不需要很多.另外要开始学习查找文献,看英文文献等,最好就是跟一个有海外留学经历,课题比较前沿的导师做点课题.具体可以咨询你们的老师

同学→_→你的英语老师叫张青吧→_→

dy/dx=2x-2xy所以dy=2x(1-y)dx所以y=(1-y)x^2+c
其中C为任意常数

我估计从来不会有人这么比,我们说 同秩矩阵是往往要对他们进行后续的分析,二阶和三阶矩阵同秩是可以说得,但是这样的同秩毫无意义.

宝宝班：infant class（也就是婴幼儿班）大一班：senior class one 大二班 senior class two中一班：middle class one 中二班：middle class two小一班：junior class one 小二班：junior class two Weclome to our ...

找老师要补考原题,这个够呛
找老师要期末原题,这个倒可以
再次点就翻出去年期末题,大题题型挨个钻吧,看着答案从目录中找书中定理啥的再找定理旁边的例题,一共才几道大题,选择填空毅然.考上大学都不笨,就是懒些罢了,不要找借口~大学老师也很忙的,一般不会有新题型的.
最后就是下课、周末实在不想学就罢了,上课时候能听就听点,没坏处的,三四年一晃就过

设 {Xn} 为实数列,a 为定数．若对任给的正数 ε,总存在正整数N,使得当 n>N 时有∣Xn-a∣

楼主很仔细,确实发现了在计算无穷大减无穷大时的细微差别,
提供了堵住那些胡乱叫嚣的等价无穷大代换的人嘴的实例.


下面的两张图片解释,第一张是按照普普通通计算无穷大减无穷大型
不定式的方法,其中采用了波罗的海,跟罗毕达求导法则.


第二张挂图,分析、追究了从-1,变成+1的来源.

甲对乙说：“我如今比你大10岁”
那么甲4年前也比乙大10岁
设甲如今x岁
x-4=(x-10-4)*2
解得
x=24
所以甲现在24岁
乙14岁

Beloved teacher,dear partners :
Hello everyone!I called # # #,the first time today I stand on the rostrum speech,and speech is the first election monitor,at this time I am excited,but also very nervous.It is a squad many students looking for jobs,the need for a capable and caring people to play,I believe I have the ability.I-12 has been a leader,we are not continue to give me this opportunity?Let me childhood diary for the whole class to stay in the unparalleled service fond memories!I warm and cheerful,loving the collective unity of the students,with love.I despise the disadvantage of poor students,not like other people's advice to me in the days to come,I will remove these defects.
If I win the election on the head when,I will use the exuberant energy,a clear mind to do this work,I will organize a series of activities such as reading,speech,etc.,and of course I do not many more.I think we should have it as a doer,not those beautiful words to describe.If I had lost that I still have many shortcomings,I will continue to self-improvement.
Tempering my work,I created a living.Dell Carnegie said,"should not be afraid of selling their own,as long as you believe that you have the talent,you should consider themselves eligible for promotion was this or that job."
Students,and trust me,support me,please vote for me,thank you!
# # #
敬爱的老师、亲爱的伙伴：
大家好!我叫＃＃＃,今天我第一次站在讲台上演讲,而第一次演讲就是竞选班长,此时此刻我很激动,也很紧张.班长是一个许多同学向往的职位,需要一个有能力有爱心的人来担当,我相信我有这个能力.我在一二年级都当过班长,大家是不是继续给我这个机会呢?让我童年的日记里留下为全班同学服务的无比美好的回忆吧!我热情开朗、热爱集体、团结同学、拥有爱心.我的缺点是看不起差生,不爱听别人对我的劝告,在未来的日子里,我将改掉这些毛病.
假如我竞选成功当上班长,我将用旺盛的精力、清醒的头脑来做好这项工作,我将举办一系列活动如朗诵、演讲等等,当然还有很多我就不多说了.我想我们都应该当个实干家,不需要那些美丽的词汇来修饰.假如我落选了,说明我还有许多缺点,我将继续自我完善.
工作锻炼了我,生活造就了我.戴尔卡耐基说过“不要怕推销自己,只要你认为自己有才华,你就应该认为自己有资格提任这个或那个职务”.
同学们,信任我、支持我,请投我一票,
＃＃＃
保证对的..!

首先这个题目就是个错题,不知道是不是你打错了...
取n=1时,
P2(x)-6P1(x)+4P0(x)
=12x^2-4-12x+4
=12(x^2-x)≠0
结论不成立哦.

5、不知道△p是什么,我猜是溶液上方水蒸气分压,那么请考虑引入的微粒数,显然尿素是最少的;
6、关键的地方看不到,到底做不做非体积功?我猜是不做;
15、只要定性考虑c和Kb的影响即可...铵根浓度大了水解平恒终态的H+不也大么...即c越大,酸性越强,然后Kb是描述碱性的,越大碱性越强,酸性越弱,pH与之正相关,注意这里是pKb...所以他还是-号...
16、我不明白你为什么算错...pOH=-lgKb(后面一截是0不用解释了吧...)=4.744,14一减即得9.255
18、简单计算一下就可以知道OH-的浓度是3.8*10^7,OH-比H+多,你说酸性还是碱性?
22、你可能缺少一个常识性的条件,浓度为多少可以认为沉淀完全?我们这边用的是10^6mol/L;
23、又有一个数看不到...我猜是1好吧..不知道你们老师是怎么教的,反正我高中老师是教我算被称为浓度商Q的一个玩意(就是像算K一样各种浓度相乘除),然后和K比较,就可以判断方向了,这一题你要把它的方程式看成两个子式的叠加就好理解了,方程式叠加K怎么算我就懒得说了.
24、ACD我知道有,B的话还真没见过,如果非要给理由我会说他的配体太多了,一个en就可以提供很多;
26、Kf*[M2+][X-]^4=[MX4]2-;
28和29完全是一回事...我想你可能比较不理解那个转移电子数n,注意,在计算过程中他们恰好被H+前面的系数次方消掉了.