Chapter 41: This student, you answer
Xu Yuan walked on the road of Qinghua campus, and as he looked around, he could see many familiar buildings in his memory.

It was March.

All things come back to life and the temperature rises.

The willow trees are turning green.

Being in it under the sunshine makes people feel comfortable.

Coupled with the fact that there were students from Qinghua passing by him from time to time, he felt the urge to enroll in school immediately.

As this thought was emerging in my mind, suddenly a building in Western classical style came into view.

He came to his senses in an instant with bright eyes.

I stood there and looked up, and couldn't help but feel a little emotional.

"We finally got to the place."

He moved his lips and murmured this, then continued walking forward.

Naturally, he was familiar with this building. As a well-known teaching building of the School of Science in Qinghua, not only were the Mathematics Department and the Physics Department buildings adjacent to each other, but it also adopted a sunken plaza design.

There is also a huge green space around the building.

Both students on campus and tourists from outside like to check in in front of this building.

However, today he was going to the mathematics building on the west side, and Tang Shihong had already told him the specific location of the classrooms.

"The grass is still not green enough." Xu Yuan walked to the front of the building, lowered his eyes to look at the green space in the sunken square, shook his head and complained.

After the evaluation, he entered the building.

It has to be said that Tang Shihong is quite popular in the school. Although there is still some time before the class starts, there are already quite a few people sitting in the classroom.

Xu Yuan came here today mainly to attend classes, especially considering that he was not yet a formal college student, so he walked into the classroom and went straight to the back rows and sat down in a random seat.

The main focus is an inconspicuous one.

But he soon discovered a new problem: he did not bring the teaching materials with him.

I came here empty-handed after dinner.

Fortunately, no one was watching him, so he didn't feel embarrassed.

Listening to the conversations of seniors around him, he found that most of the people who came to attend the class were undergraduates, and in addition to students from the Department of Mathematics, there were also many students from other departments.

He should be planning to take the postgraduate entrance examination.

"Professor Tang is here."

At this moment, someone shouted, and the whole classroom suddenly became quiet and silent.

Xu Yuan looked towards the door and saw the familiar figure of Tang Shihong walking in.

He was still dressed the same as at the opening ceremony two days ago, holding a very ordinary plastic water cup in his hand. Judging from the color of the cup, it must be quite old.

"There are quite a few people attending the class today, so let's stop talking nonsense and get started."

Tang Shihong walked to the podium, put down what he was holding, raised his eyes and looked around purposefully, then found the familiar figure in the back row, then he put on a smile and started today's class.

Mathematics courses in college are definitely much more difficult. Tang Shihong talked about plane geometry and Minkowski inequality in his class.

As the discussion on the issues was quite in-depth, even Xu Yuan had to concentrate on listening.

Make sure you keep up with Tang Shihong's pace.

The Minkowski inequality is an important inequality proposed by the German mathematician Minkowski.

Its theoretical source is convex geometry. This inequality shows that the space composed of p-time integrable functions is a normed vector space. Although it is not as famous and commonly used as the Cauchy inequality, it is a very important mathematical inequality.

With the help of the mathematical knowledge he had learned from the postgraduate entrance examination in his previous life, Xu Yuan gained a lot after listening to the lecture.

But it’s hard for others who signed up for this class.

Students from our department are relatively better, but those from other departments are a little more advanced and there is not much difference between them and listening to a foreign book.

My head is about to explode.

By the second half of the course, I was basically in a trance.

It is hard not to wonder if this class will make me give up the idea of ​​taking the postgraduate entrance exam. After all, mathematics is too difficult.

“A convex body is a bounded closed set on R that satisfies the convex property.”

……

"Given the lengths of the sides and the directions of the normals, the existence of an n-dimensional polyhedron can be established by the assertions I have just made..."

Tang Shihong gave a brief summary at the end. When he turned back to the classroom and saw that many people were drowsy, a look of disappointment appeared on his face.

It wasn't until I noticed Xu Yuan's unsatisfied look in the back row that I felt much better.

At this moment, I felt more and more that letting Xu Yuan come to attend the class was the right choice.

After all, as a teacher, who wouldn’t want more students like Xu Yuan?

The next second he seemed to have thought of something, picked up the chalk and quickly wrote the formula on the blackboard again.

"Let f, g∈L(E) then ||∫+g||p≤||∫..."

"It's easy to fall asleep in the afternoon, so let's actually prove it. Is there anyone willing to come up and do the calculation?"

When Xu Yuan saw the question on the blackboard, he immediately understood that it involved the proof of Minkowski's inequality.

But for some reason, even though Tang Shihong didn't look at him specifically, he always had a feeling that it was directed at him.

I shook my head to dismiss the thought and tried to solve the proof problem in my mind.

If you ask him why he didn't calculate on a piece of scratch paper, it's naturally because there was nothing on the desk in front of him.

As for going on stage to prove it, that was not even within his consideration.

He came here just to attend the class today.

I really don't want to be noticed by a group of seniors before I even enter the school.

However, the seniors Xu Yuan mentioned were not in a good situation at the moment.

My head was already confused after listening to what was just said, and now I have to answer the questions, how can I have any idea?

Undergraduate students in the mathematics department might still be able to try the calculation, but others decisively chose to give up.

It was not until Tang Shihong's voice sounded again that everyone turned their heads and looked towards the back row in the direction of his finger.

"The boy in the last row wearing black, tell me how to solve this problem?"

"me……"

Xu Yuan was caught off guard when he met everyone's gaze.

I didn't expect my feeling to be so accurate.

In order to let him cheer up the people in the classroom, Professor Tang actually wrote a proof question.

Now we have to force things to happen.

The thought stayed here, and he had no choice but to stand up from his seat.

Other people around noticed Xu Yuan's stunned expression and the empty seat without even a pen. It didn't look like he could answer the questions.

I suddenly felt that this classmate might make a fool of himself.

There was a little more sympathy in his eyes.

Poor child, he was still confused when he was enlightened by Professor Tang.

But the next second after this thought came to his mind, Xu Yuan suddenly answered with confidence.

"It is not difficult to prove the Minkowski inequality. It can be proved based on the integral form of Helder's inequality."

After saying this, he walked towards the podium under the sudden surprised looks of the people around him.

Since he was personally named by Professor Tang, he certainly couldn't reply that he couldn't prove it. It was not his style to give in when it came to mathematics.

When Tang Shihong heard this, his eyes immediately lit up, and he quickly moved to the side and looked at Xu Yuan expectantly for proof, while the people in the audience began to become curious about Xu Yuan's identity.

(End of this chapter)