Xueba starts with change

Chapter 171 End of Written Exam (Two in One)

noon.

Chen Zhou and Yang Yiyi returned to Yanda University and had lunch in the cafeteria.

Then, he went back to the dormitory.

Chen Zhou glanced at the time, it was past 12:[-].

The exam starts at 2:[-] p.m., but like the team competition, the individual competition also requires entry half an hour earlier for each subject exam.

In such a short time, Chen Zhou didn't want to do other things anymore.

I simply lay down on the bed, preparing to take a nap, and refresh myself for the afternoon and evening exams.

He didn't have to worry that Zhao Qiqi and the others would wake him up when they came back.

Because, he had already called three people, and all three of them handed in the test papers at 12 o'clock.

It was already 12:15 when they walked out of the math center.

They didn't plan to go back to school anymore, so they found a nearby restaurant to solve the problem.

When the alarm clock rang, Chen Zhou opened his eyes and got out of bed.

Looking at the time, he slept for about half an hour.

Just right.

A nap of half an hour is enough, and it is not good to sleep more or less.

After washing his face, Chen Zhou called Yang Yiyi.

The two met and went to the math center.

At 2:[-] in the afternoon, Qiu Sai continued.

The first subject of the individual competition is Analysis and Partial Differential Equations.

Chen Zhou roughly scanned the entire test paper.

The test center of the first question is related to measurable functions.

The measurable function refers to the definition of t∈R, E[f>t] is a measurable set, then the function f is a measurable function.

Therefore, combined with topic information fn∈L(R) is a sequence of measurable functions, and fn→f is continuous everywhere.

Chen Zhou can basically determine the solution to this problem.

Then use the assumptions given at the end, ║fn║L→║f║L.

Chen Zhou quickly wrote his answer on the test paper.

After writing, read it again.

After confirming that there were no detailed mistakes, Chen Zhou started the next question.

The second question is about continuous functions and definite integrals.

It didn't take much effort, Chen Zhou got it done.

The difficulty of this question is about the same as the first question.

Then there is the third question.

Seeing this question, Chen Zhou raised his eyebrows.

interesting.

The topic information of this question is an inequality.

【|f(z)|≤|z||Im(z)|】

What is then required is the largest "z" value such that this inequality satisfies the condition.

Often such questions with less information on the topic are more likely to lose their clues.

But Chen Zhou couldn't. After a little thought, he understood the meaning of this question.

Immediately, began to write.

Replace the thoughts in your head with the steps of disintegration.

Write out formulas one by one, step by step.

The fourth problem is the problem of holomorphic functions.

When Chen Zhou started browsing, he thought it was a coincidence.

He just finished a dissertation on a subject related to holomorphic functions.

This brings us to the problem of holomorphic functions.

Send sub-questions.

Fifth question.

Question about Hilbert spaces.

This is also a question that Chen Zhou is interested in.

The reason for interest is mainly Hilbert space.

Although this question is simple after all, it also provided Chen Zhou with some ideas.

For the next step, the direction of his subject research.

After finishing this question, Chen Zhou completed the tasks of this exam in order.

Looking back, from the fifth question to the first question.

Chen Zhou checked again.

After all, what Yang Yiyi told them also applies to himself.

People tend to overlook obvious mistakes.

After carefully checking the steps and details of the five questions, Chen Zhou was about to get up and hand in the paper.

To his surprise, Professor Shang, whom he had met in the morning, stood by his side again this time.

Seeing that he was about to hand in the paper, Professor Shang stretched out his hand directly.

Chen Zhou handed the test paper to Professor Shang and smiled at him.

Not long after Chen Zhou walked out of Professor 1308, he saw Yang Yiyi also come out.

Chen Zhou glanced at the time, and a smile appeared on the corner of his mouth: "Analysis and partial differential equations are indeed what this girl is good at..."

I went shopping with Yang Yiyi at the Morningside Mathematics Center of Huaguo Academy of Sciences, and when the exam was over, the three of Zhao Qiqi came out.

The five of Chen Zhou found a restaurant together.

After dinner, because Yang Yiyi didn't sign up for the probability and statistics exam, she went back to Yanda first.

The remaining four, Chen Zhou, went back to the math center and waited silently for the entrance exam.

There was a tacit understanding, and the three of Zhao Qiqi never mentioned the exam in front of Chen Zhou.

Even if they made all the test papers, they didn't say a word.

After all, the past is vivid...

Wait until 6:[-] p.m.

The second subject of the individual competition, probability and statistics, begins the exam.

How should I put it, Chen Zhou felt that the test paper for this subject must not have been taken seriously by the person who wrote the test paper.

Whether it is an individual competition or a team competition, the test papers for this subject are very simple.

For example, the topic of flipping a coin can appear here.

The title means:

[Toss an even coin until the side with flowers appears twice in a row, how many times does the coin flip? 】

There are many solutions Chen Zhou can think of for this problem.

The most common is the probability formula.

Secondly, there is a method of bifurcation tree recursive column equation.

In general, the difficulty of the probability and statistics test paper is not even as difficult as the final test of the probability theory course that Chen Zhou took last year.

Of course, Chen Zhou can also guess the reason for this situation.

After all, this is only the preliminary round, and the people facing it are college students from all parts of Huaguo.

After the probability and statistics exam, Chen Zhou waited outside for a short time, when Li Li handed in the exam.

Then came Zhu Mingli, and finally Zhao Qiqi.

Chen Zhou asked with a smile: "Didn't you wait till the end?"

Zhao Qiqi also smiled and replied: "Aren't you afraid that Brother Chen will wait too long?"

Zhu Mingli also said: "Submit the test paper early and go back early."

Only Li Li said silently: "The topic is too simple, I'm sorry to waste time..."

Chen Zhou smiled and looked at Li Li upon hearing this.

This is the truth...

Chen Zhou and the others took the bus back to Yanda University, and when they entered the dormitory, it was exactly 9 o'clock in the evening.

Chen Zhou sent a message to Yang Yiyi, telling him that he had returned to the dormitory.

This is the minimum respect between lovers.

Not long after, Yang Yiyi replied.

【Hmm, then you can read a book, and then wash up and go to sleep. 】

Chen Zhou replied with an "OK" expression.

Speaking of reading books, Chen Zhou doesn't really want to read physics textbooks now.

But he has already finished brushing up the textbooks for the undergraduate courses of the Department of Mathematics.

But the subject has not been determined yet, and he has no direction for the time being.

After thinking about it, Chen Zhou turned on the computer and searched for "Hilbert's 23 questions".

The words Hilbert have a magical charm in the mathematics world.

He is one of the greatest mathematicians of the 19th and 20th centuries.

This man is almost a perfect man of mathematics. His footprints are all over the frontier fields of modern mathematics, and his mathematical ideas have deeply penetrated into the entire modern mathematics.

Hilbert's 23 questions are the 1900 most important mathematical problems proposed by Hilbert at the Paris Congress of Mathematicians in 23.

In a sense, Hilbert's 23 questions have guided the direction of mathematical research after the twentieth century, and its influence has continued to this day.

In 1976, among the top ten achievements in American mathematics selected by American mathematicians since 1940, Hilbert's 1st question, 5th question, and 10th question each occupied three.

Including the seven millennium problems proposed by the Clay Institute of Mathematics in the United States, it also echoed the 1900 questions raised by Hilbert in 23.

Its influence can be seen from this.

Chen Zhou looked at the information he found.

Although more than a century has passed, the subject of mathematics has also made great progress.

However, among the 23 questions, a total of 17 were accepted and all resolved.

There are still 6 problems left, which have not been completely resolved.

It can be seen that time is not a sufficient condition for solving problems, it is only a necessary factor.

Just like Fermat's last theorem, after more than 300 years of precipitation, it was finally solved by Wiles in 1995.

Chen Zhou looked at the discussion behind these questions with some emotion.

The existence of these problems has already surpassed the meaning of the problem itself.

In the research process of these problems, the new mathematical tools and research methods born are even more important than some problems.

Like the problem of "proof of the transcendence of certain numbers".

Its correctness was independently proved by several mathematicians as early as 1929 and 1935 respectively.

But the research on transcendental number theory is far from complete.

The study of this problem has also become a part of transcendental number theory.

There is also the problem of "prime number separation".

Riemann's conjecture, Goldbach's conjecture, and the twin prime problem.

These are all unresolved issues.

However, in the process of solving these conjectures, whether it is the obtained three prime number theorem or the important improvement of the sieve method, they are all extremely important and rare achievements.

Holding the mouse and sliding the scroll wheel, Chen Zhou sorted out the 23 unsolved problems out of the 6 questions.

It's not that he intends to choose one of these six issues as a research topic.

Rather, he hopes to gain some direction from it.

Then, move closer to these real problems.

Moreover, the system tasks only guide one direction each time, and Chen Zhou has to do everything by himself.

Therefore, Chen Zhou intends to establish a systematic research idea for the subject.

From the topic selection of the topic, to every step after that.

He intends to gradually develop, or form his own research style.

This is also Chen Zhou's decision after careful consideration.

After all, judging from the last mission, the experience rewarded by the system ultimately depends on the value of the subject.

Of course, you have to go deeper step by step.

After Chen Zhou finished taking notes, he searched for some related literature and similar content.

After finishing all these, Chen Zhou stretched himself.

Glancing at the time, it was past 10 o'clock.

I just wondered why Yang Yiyi didn't come to remind me of the news.

I heard the phone vibrate.

Chen Zhou picked it up and took a look, Yang Yiyi sent it.

[Happy, it's time to sleep, be good, hee hee. 】

Looking at the message, Chen Zhou smiled slightly, tapped his fingers quickly, and replied one.

【Well, happy Yiyi, let's go to bed...】

As soon as she sent it, Yang Yiyi came back.

【Okok good night. 】

Chen Zhou: [Good night. 】

The next day, Sunday, March 3.

Admission at 9:9 a.m., exam at [-]:[-] a.m.

The third subject in the individual competition is geometry and topology.

After Yang Yiyi finished this subject, her whole written test was over.

She didn't apply for the last two subjects in the afternoon.

For the geometry and topology test papers, Chen Zhou's eyes brightened.

The test paper was written by a good person, the paper was neat, and the questions were very short.

It's very comfortable to look at...

The first problem is about the product of spheres.

Chen Zhou raised his pen to calculate, his thinking was clear and his calculations were rigorous.

It didn't take much time to solve the first question.

Then there is the second question.

Three-dimensional manifold proof problem.

Manifolds describe geometric shapes in mathematics.

The second problem is solved, and the third problem is reached.

On unbounded smooth manifolds and vector fields.

It wasn't too difficult. After Chen Zhou finalized his ideas, he wrote down the problem-solving process on the test paper.

The fourth question returns to the surface problem, and proves the standard sphere according to the average curvature.

Quick, get it done!
The fifth question is about the Riemannian manifold, that is, the problem of Riemannian geometry.

Chen Zhou took a second look at this question.

Not because of the title.

Instead, he is interested in Riemannian geometry, just like the Hilbert space in the analysis and partial differential equations yesterday.

It was the same as last night when Chen Zhou searched for literature and searched in the same direction.

With the release of the new missions of the system, his goal of participating in the Qiu competition is more to find the direction.

In the morning, after Chen Zhou and Yang Yiyi handed in the papers ahead of schedule, they went back to Yanda together like yesterday.

In the afternoon, Yang Yiyi planned to go to the professor to follow up on the subject of mechanics.

And Chen Zhou took a nap in the dormitory, and then rushed to the Morningside Math Center.

At 2:[-] in the afternoon, the fourth individual exam, algebra and number theory, began.

Chen Zhou complained a lot about this test paper.

First of all, unlike other subjects, this test paper is not 6 questions to choose 5 questions.

It has only 5 questions in total.

It is also different from the test papers of the team competition.

However, each of its 5 major questions consists of at least 4 small questions.

Well, the third question is 3 small questions, but in the third small question, there are 3 more small questions...

Therefore, this test paper is the one that Chen Zhou has tested the most among so many subjects.

5 questions, printed 3 sheets of A4 paper...

Another point that Chen Zhou couldn't help complaining about was that the beginning of this test paper was also different from other test papers.

At the beginning of this test paper, there is a sentence of persuasion.

[This 160-point test paper is just to test how much you know, not how much you don't know. You don't need to complete all the questions, you just need to do your best. 】

Chen Zhou felt that there were at least two meanings.

The first level is that we issue this test paper for the sake of improving yourself. It is normal for you not to do it, as long as you do your best.

Another layer is that you need to make sure you know the question before solving it.

If you don’t know it, don’t write any more. We have asked so many questions, so don’t delay our marking time...

Chen Zhou shook his head slightly. The candidates who came to participate in the competition must want to get as many points as possible.

The sentence in front of this test paper is really too unfriendly...

Chen Zhou didn't quite understand the meaning of this passage, so he could only classify it as a kind of examination method...

Looking around, Chen Zhou saw a few candidates whose emotions had changed.

Withdrawing his gaze, Chen Zhou straightened out his thoughts and began to answer the questions.

This test paper is mainly about commutative groups, orthogonal complex matrices, complex matrix spaces, prime number problems, and unique factorization domains.

It may be difficult for others, but for Chen Zhou, these are just an ordinary test of his knowledge.

The best response to the sentence at the beginning of the test paper is to get a full score on this test paper!

When Chen Zhou handed in the paper and left classroom 1308.

In the classroom, I thought I was used to the candidates who kept handing in their papers in advance.

At this moment, the mood is complicated again.

This test paper is the most difficult one since they took the test in the past two days.

At 5:[-] p.m., the exam ends.

Chen Zhou and Zhao Qiqi reconciled and went to the restaurant from yesterday.

However, apart from Chen Zhou, Zhao Qiqi's appetite seemed to be affected by the exam in the afternoon.

Chen Zhou thought about it, but he didn't say anything to comfort him.

This kind of thing that is affected by the exam, comfort is the most useless.

At 6:[-] p.m., the last test of the individual competition is also the last test of the written test stage of the Qiu Sai.

Applied and Computational Mathematics, beginning the exam.

In fact, this test paper is mainly an assessment of the application of mathematics.

Includes linear models, numerical fitting problems, and more.

Although it's not what Chen Zhou is good at, but with the experience accumulated in the last UPC competition, he can handle it with ease.

9 pm.

Chen Zhou, who had been waiting for quite a while, finally saw the figures of Zhao Qiqi, Zhu Mingli, and Li Li.

　I wish all the students of the college entrance examination, the next two days of the college entrance examination will go smoothly, the flag will be successful, and the road will be Changhong!come on!

　　
　
(End of this chapter)