Chapter 358: problem

Chapter 358
Twenty minutes of essay presentation time.
Cheng Nuo quickly explained the core content of his graduation thesis to the four defense teachers.
The four also nodded frequently.
No matter from which aspect, Cheng Nuo's performance in this link is sufficient to describe it as impeccable.
"...The above is my statement about the paper this time."
Stuck in time, Cheng Nuo finished in the last ten seconds.
The four defense teachers in the audience also sat upright in an instant, with serious faces, preparing for the last part of the defense: the defense teacher asked questions.
This is the most important part of the three stages of defense, and it is also the existence that countless graduates call the "ghost gate".
One by one, the unusually difficult problems are thrown at you like a gun, and you have to gather your energy to face them with a smile.
Especially the kind of questions that sounded dumbfounded, it makes people want to answer without knowing how to speak.
There are two forms of questioning in the graduation defense.
One is that the instructor writes the questions that will be asked on a piece of paper, and for each question, candidates have about five to ten minutes to prepare.
After you are ready, you can answer again.
The other form is to test the academic level of students even more.
That is, the teacher in the defense group asked questions on the spot, and the students answered on the spot, without any, even one minute of preparation time.
This form is undoubtedly extremely cruel to students participating in the defense, but it is the most effective test of their four-year undergraduate study results.
However, taking into account the question of graduation rate, half of the answering and questioning sessions of Tsinghua Academy of Mathematics are a mixture of two question forms.
Two question questions are left for students to prepare their words.
The other two topics completely test the students' on-the-spot performance.
A few days ago, when the first few students who reported today participated in the defense, they all arranged this way.
However, for Cheng Nuo, this enchanting genius, obviously needs to be treated differently.
If Cheng Nuo is left with time to prepare, this is too sorry for Cheng Nuo's genius name.
Therefore, President Wei proposed and the four people unanimously decided that Cheng Nuo's answering questions will be answered directly on the spot.
"Student Cheng Nuo, are you ready?" Dean Wei asked with a faint smile on his mouth looking at Cheng Nuo on the bench.
Cheng Nuo took a deep breath, "Ready!"
What should come is always coming.
Besides, with Professor Fang and Dean Wei here, Cheng Nuo guessed that the level of difficulty of the problem might be very high!
"Then let me ask the first question!" Cheng Nuo didn't expect that Professor Fang would be the first to raise the issue.
Professor Fang sat on the seat of the teacher in the defense group and said with a smile, "Cheng Nuo, are you okay?"
"No, no." Cheng Nuo smiled bitterly and waved.
Professor Fang nodded, and while flipping through Cheng Nuo’s paper, he asked,
Inference 10 drawn on page 15 of your paper, the specific reasoning steps are too simple, you can use specific formulas to prove it on the spot. Do you do it again?"
The specific proof method of Corollary 10? It's easy!
Sure enough, it is more reliable to be a teacher. The first question is not too difficult for yourself.
Cheng Nuo smiled lightly and nodded lightly, "No problem."
After speaking, Cheng Nuo picked up a piece of chalk on the podium and began to write swiftly on the blank side of the blackboard.
This is not a lecture, you don’t need to write and talk.
Cheng Nuo only needs to write out the detailed derivation steps of Inference 10.
This is no problem for Cheng Nuo.
Although Corollary 10 is a corollary that was "discarded" in the proof of Bertrand's hypothesis, Cheng Nuo still remembered the specific steps of the proof.
【Because n≥3 and 2n/32n, there is only one term i=1 in the summation formula, namely: s=floor(2n/p)-2floor(n/p). Since 2n/3p≤n also indicates that 1≤n/p3/2, so s=floor(2n/p)-2floor(n/p)……]
[……Θ(n)≡Σp≤nlog(p)nlog4,……To sum up, we can get Πp≤Np=(Πp≤m+1p)(Πm+1
Get it done!
Cheng Nuo turned around and wanted to throw the chalk head back into the chalk box handsomely, but when he thought this was the graduation defense scene, he took his raised hand away and stood awkwardly.
In the audience, the four defense teachers stared at the half blackboard filled with Cheng Nuo for almost a minute.
With their mathematical ability, it is not difficult to quickly understand and understand the formula written by Cheng Nuo. Moreover, they themselves have a certain degree of understanding of the content of Cheng Nuo's paper.
Professor Fang smiled and said, "Yes, I am very satisfied."
After asking a question, Professor Fang did not hold on to Cheng Nuo again, nodded in satisfaction, and stopped talking.
The next question is the other two professors of the defense team.
Cheng Nuo easily answered all the questions raised.
It's not that their question is not difficult enough, but that Cheng Nuo is too abnormal.
In fact, the two questions they asked, even if a few top students who graduated from the academy were born to answer, would be tricky.
But what they faced was Cheng Nuo, a student far beyond their cognitive genius.
With such a difficult problem, Cheng Nuo can slash melons and vegetables all the way.
But Cheng Nuo, who easily managed the first three questions, did not show too much joy on his face, because he knew that the biggest difficulty of his graduation defense this time had not yet appeared.
That was Dean Wei. Since he was willing to go off the court to participate in the defense, he definitely did not just want to see how Cheng Nuo pretended to be at the defense.
The first three questions are just appetizers, and the last question is the ultimate boss!
It was Dean Wei's turn to ask questions. He stared at Cheng Nuo not far away, and smiled like a villain.
There was a few cold sweats on Cheng Nuo's forehead.
Dean Wei took out a document from the briefcase on the side in an unhurried manner, put it on the table, pointed at it, and asked with a smile, "Student Cheng Nuo, do you know what this is?"
Cheng Nuo shook his head, "Students don't know."
Dean Wei waved to Cheng Nuo, and when Cheng Nuo came closer, he handed the folder to Cheng Nuo, "Take it and have a look."
Cheng Nuo took it suspiciously and opened it.
When seeing the title of the file, his pupils shrank suddenly.
Then ~EbookFREE.me~ he hurriedly opened the first page, his face changed again.
Dean Wei smiled unhurriedly and said, "After I got your paper that day, I also became a little interested in Bertrand's hypothesis proof method."
"Hey, the paper in your hand is another Bertrand hypothesis proof method I wrote in three days."
hiss!
Not only Cheng Nuo, but the other three professors also took a breath.
"Don't be so surprised, I haven't finished it yet!" Dean Wei cursed with a smile, "This paper, uh, how do you say it, is a failure, because I only found out that there is some logic in the paper after I finished writing. error."
Dean Wei looked straight, "And Cheng Nuo, the test I give you is to find the logical errors in this paper within half an hour."
"Of course, if you can correct this logical error and make the whole paper logical, I will give you full marks for this graduation defense!"