An Expert Is actually By My Side

　　 "Be a little more magnanimous. If you are late, you will be late. Can't you walk in through the front door openly?"

　　淦!

　　 I am not afraid to interrupt your class.

　　 Isn’t it an international practice to say that entering through the back door is late?

　　 A pair of glances came over, Hao Yun was a little embarrassed even though he had a thicker skin.

　　 Just when he was hesitating whether to walk through the front door again, Li Xuesong on the stage coughed and continued with a stern face.

　　 "How about homework?"

　　Work, homework?

　　 Upon hearing these words, Hao Yun's face suddenly became embarrassed.

　　 "Uh, forgot to bring it."

　　 Forgot to bring it?

Ha ha!

　　 If I didn't write it, I didn't write it, and I was looking for such a low-level excuse.

　　 Looking at Hao Yun with a faint smile, Li Xuesong chuckled and continued: "Forgot to bring it? That's OK, you mean you wrote it? Anyway, it's just one question, so you can write it now, right?"

　　 said, his index finger tapped on the blackboard.

　　 "Come here to write."

　　 Hearing these words from the old professor, there was a commotion in the class, and many people whispered to each other.

　　 Hao Yun, who stood in the back row, couldn't hear what they were talking about. He just wanted to vomit the old professor and he didn't know what he was thinking about today. I haven't done anything that is damaging to the world, but it's a minute or two late to make things so difficult.

　　 Looking at Lao Li's smile, he knew that he was doomed to escape this disaster today.

　　 severely scolded the second person who had followed his draft in his heart, Hao Yun sighed, and finally walked towards the podium.

　　As he passed the front row, he noticed that Zheng Xueqian was shaking him frantically, and poking his phone's screen vigorously, as if to beckon him to read WeChat.

　　 [Are you crazy? ! Actually come up? No one wrote that question! 】

　　 Although he can guess, this good brother probably sent himself the answer to his homework, but he has already got here, and he obviously has no chance to take out his phone.

　　 Hao Yun returned him with a relieved look, and communicated with his eyes.

　　【Don't worry, I'm fine. 】

　　 met the "confident" eyes, Zheng Xueqian blindfolded for an instant.

　　 Fuck?

　　What does this guy mean?

　　 Could it be...Is it really written out?

impossible!

　　The question that He Shen didn’t even write...

　　 The touch of his eyes was just a moment of effort. Before he could confirm whether he would be wrong, Zheng Xueqian watched Hao Yun stand on the stage.

　　Receiving the chalk from Lao Li, Hao Yun stood in front of the blackboard for a while, then suddenly turned back a little embarrassed.

　　 "Uh, what's the topic... I didn't memorize it."

　　 As soon as he heard this, Li Xuesong smiled suddenly, and he pointed his chin to the stage as he said to see when you were acting.

　　 "There are so many on the desk, you can just copy a copy."

　　 It's okay to copy one...

　　 Aren't you afraid that I will read the answer?

　　 Hao Yun, who picked up the homework on the top, muttered a few words in his heart, but within a second of turning it over, he was taken aback.

　　 Good fellow, just wrote a "solution".

　　 Is this not going to be normal?

　　 somehow hide the book underneath!

　　 Looking at the name again, it was actually Liang Ziyuan.

　　 wrote down the title silently, and Hao Yun helped him tuck the homework book to the bottom very graciously.

　　 Seeing all the little movements of the student, Li Xuesong smiled without breaking through, just raised his eyebrows and continued.

　　 "Do you know the topic now?"

　　 "Uh, I remember."

　　 "Remember? Okay, then don't talk nonsense, hurry up and write!"

　　 is not a particularly difficult question, even there are only a few letters, and the whole information of the question can be explained clearly in two sentences.

　　 Hao Yun didn't think much, turned around and copied the question on the blackboard, and then read the question from beginning to end again.

　　 However, this copy does not matter.

　　 When he finished copying the title and read it again, he was completely stunned.

　　 [Suppose positive integers a and b satisfy (a2+b2)/(ab+1)=k∈N, and prove that k is the square of a certain positive integer. 】

　　 good fellow.

　　This question...

　　 Is it familiar?

　　 Seeing that Hao Yun hadn’t moved for a long time, Li Xuesong thought he would not, so he smiled and joked: “If you can write it out, you won’t have to take my class in the future, and you will receive all the credits.”

　　 Hao Yun swallowed, couldn't believe it and asked.

　　 "...really?"

　　 "Heh, should I lie to you?"

　　 Then I really wrote...

　　 After confirming that this guy didn't seem to be speaking an irony, Hao Yun hesitated for a moment, and finally put the chalk on the blackboard and started to move his pen.

　　 [If k is not the square of a positive integer, then a≠b. 】

　　 [Considering the indeterminate equation a2-kab+(b2-k)=0, if a=b, then k=1 can be deduced, so it contradicts the assumption. 】

　　[Therefore, let us set a>b>0, and take a set of solutions (a0, b0) to minimize a0+b0...]

　　Although he copied this question in the draft book before, Hao Yun never took the time to read it carefully, otherwise he would not be surprised if he left it here.

　　 The reason for being surprised is also very simple.

　　Because this is not only an original problem, but also the sixth problem of the IMO International Mathematics Competition in 1988 on the earth of the previous life!

　　 As for why he knew...

　　 is not because he participated in the competition, but because only yesterday, he saw it in the high math textbook full of notes, and finally did it by himself.

　　 He even remembered that this question was copied in the blank space at the end of the page of Veda's theorem.

　　 According to Professor Lu’s slightly ridiculous comment, no one from the main examination committee made this seemingly simple number theory problem. Finally, it turned to four number theory experts from Australia, the host of the competition, for a long time.

　　 Because the experts couldn't solve this problem within the specified time, this problem became a legend.

　　 There were hundreds of contestants in total. In the end, only a dozen of them chose to write out their answers by hand. One of them even got a special prize from the main examination committee of the competition for his beautiful answers.

　　 And at this moment, the solution he was writing on the blackboard was the "mark answer" that was awarded the special prize that year.

　　 It’s very interesting that, according to Professor Lu’s written description, the dozen or so contestants who wrote the answers eventually became well-known figures in the mathematics field. When commenting on this little-known past, the professor also wrote with emotion——

　　 [Usually, mathematics is a product of intuition, but some counter-intuitive propositions are not ruled out. Just as our common sense always tells us that contradiction is unreliable, our common sense occasionally deceives ourselves against common sense. 】

　　 [It just surprised me a little. Even Tao Zhexuan, who shouldn't lose to this question, was unfortunately planted in its hands. 】

　　Although Hao Yun had no particular interest in mathematics, and Hao Yun had never heard of the names mentioned by the professor, but he still got a reliable conclusion from the limited commentary.

　　 This notebook is probably the relic of a celebrity in a previous life-or even a great man?

　　Thinking about it this way, I suddenly felt like a holy relic.

　　 The only pity is that after he finished reading the notebook, the system didn't even leave him a trace of ashes, and directly erased the existence of the thing from the world.

　　 Just as Hao Yun was thinking wildly while writing the answer on the blackboard according to his impression of problem-solving ideas, Professor Li Xuesong standing next to him looked stupid.

　　 It’s fine if it’s scribbling. At most, after this guy finishes writing, he laughs at the side...Oh no, just criticize and educate.

　　 But this guy wrote it, he couldn't find any fault!

　　 even think...

　　 seems to make sense? !

　　 Especially when Hao Yun wrote to the fourth line, his whole face changed.

　　 Fuck! ?

　　 This question can be solved this way?

　　 He was not the only one who was shocked, but also He Ping standing in the audience.

　　 staring at the blackboard intently, both eyes straightened up, and he couldn't help but mutter in a low voice.

　　 "Disprove? It's actually a contradiction method?! Impossible, I tried to disprove before—"

　　 "That's it... I understand... That's it..."

　　 Zhou Xuan and Wang Ziyi, who were sitting next to him, looked at each other and exchanged a bewildered glance.

　　 Zheng Xueqian, who was sitting in the back row, swallowed, and his nervous pen was almost crushed.

　　 is not to cheer for Hao Yun, but I didn't expect this guy who sleeps diagonally to be so awesome!

　　 careless...

　　 Zhu Kening and Liang Ziyuan didn't have any special reactions. One was not interested at all, and the other couldn't understand it. They just thought it seemed a bit awesome.

　　 The entire 1801 and 1802 classes are silent.

　　 Regardless of whether it is a real learner or a fake learner, watching the process of writing on the blackboard, almost everyone is stunned.

　　 didn't pay attention to the expressions on the faces of the people behind him. He concentrated on Hao Yun on the blackboard, feeling that he was entering an unprecedented state.

how to say?

　　 It's as if the whole world has slowed down.

　　 Only his thinking is still accelerating...

　　 is it because of [Mathematics Proficiency]?

　　 It turns out that this is the effect of quantitative change caused qualitative change...

　　Although his intuition tells him that the accelerated thinking can be faster, and it can be further developed until it finally touches the realm of the so-called gods! But for him at this moment, even this degree of acceleration is completely enough.

　　 What I put in front of me is just a topic I have written, and it is far from creation.

　　 A trace of enlightenment gradually rose in his heart.

　　 Until this moment, Hao Yun finally understood a little bit of what kind of existence this so-called superhuman system is.

　　 The hour hand on the wall is moving every second.

　　 has been around for almost three laps, he stopped the chalk in his hand, and turned his head to look at Lao Li who was standing next to him.

　　 "...I have finished writing."

　　 I don't know if I didn't hear what I said, Professor Li Xuesong didn't react, even his eyebrows didn't move.

　　 In order to confirm that the old man was asleep, Hao Yun asked politely.

　　 "Is there anything wrong with the steps?"

　　 After hearing this question, Professor Li Xuesong finally recovered.

　　 I saw him staring at Hao Yun with straight eyes, then looked at the blackboard, and then moved his stiff neck like shaking his head or nodding, and spit out a word from his mouth.

"no problem……"

　　 Hearing these words, the stone hanging in Hao Yun's heart finally fell on the ground.

　　 deserves to be Jiang Da.

　　 It’s true that it’s some awesome!

　　 The previous life had to be put on the IMO competition to add to people's exam questions. In this life, it is only worthy of the after-class thinking of the first lesson of high math.

　　 There was a surge of pressure, and Hao Yun was too embarrassed to ask the professor if he would really not use it in the future. After saying "then I will go down", he slipped off the platform quietly.

　　 The whole classroom is silent.

　　 I don't know who started it, but applauded.

　　 He Ping sat back with his eyes straight, not knowing what he was chanting in his mouth.

　　 Going back to the last row and sitting down, Hao Yun always felt that there were a lot of people around him watching him. This also made him feel uncomfortable for a while, who had always had a low sense of presence.

　　 Fortunately, the applause lasted only a short while.

　　 As Professor Li Xuesong returned to the podium without saying a word, the students in the classroom also re-entered the state, staring at the blackboard carefully preparing to listen to the lecture.

"The answer is the same as that written by this classmate. It's basically a standard answer... You copy it. If you don't have time to copy it, take a picture. UU reading www.uukanshu.com won't ask him. I'll just ask him for the specific details. Stop talking."

　　 "Turn to page 12 below, we continue to talk about the last class..."

I don’t know if it was stimulated. In the second half of the class, Professor Li Xuesong unexpectedly did not repeatedly nag those “young people now” and “how are our old men in the old days” and other incomprehensible things. .

　　 It’s just that, I don’t know if it’s his own illusion. Hao Yun always felt that he was absent from the podium?

　　 Or say that the soul is not in the house.

　　 Thinking of this, Hao Yun couldn't help but worry a little. Did his late behavior anger him?

　　 But shouldn’t it?

　　 People who are not sages and sages can do nothing, not to mention that I was only late, so I should admit my mistake, and my attitude is correct! If this can still be irritated, it would be too careful, right?

　　 and Zheng Xueqian...

　　 This guy keeps looking back at himself in class, which makes Hao Yun really embarrassed.

　　 The bell between classes finally rang.

　　Professor Li Xuesong dropped the high mathematics book without saying a word and left.

　　 Everyone thought he was going to solve his internal urgency, but he didn't expect that after five minutes, after the class bell rang, it was a doctoral student's younger brother who came.

　　 Look at the hair style that is passed down in the same vein, his students can't go wrong.

　　 Sure enough, his opening remarks also confirmed the guesses of the big guys.

　　 "Professor Li Xuesong has something to do. I will teach you the second half of the class."

　　 Seeing the little Mengxins in the classroom smiled, the doctor picked up the textbook on the desk and scratched the back of his head.

　　 "Uh, the professor was a little hurried away just now..."

　　 "Who can get up and tell me, where did he talk just now?"