Do you understand Euclid today?

When Lin Qianshu walked up to Guan Ming, Guan Ming was bowing his head to calculate a complex function problem. His pen was flying on the draft paper, which made Lin Qianshu unconsciously think of Jiang Yizhi who he saw when he opened the office door this morning.

Hearing the sound of the stool beside him, the boy with blue glasses turned his head in a daze, and found that Lin Qianshu had sat beside him at some point, his face flushed red again, and he stammered, "Hello, Mr. Lin .”

Thinking back to the radar of "Brother Lin" and Jiang Yixing who was full of disgust, Lin Qianshu felt that this one in front of him looked like a serious student.He smiled and raised his hand to pat Guan Ming's shoulder: "Don't be nervous, just sit here and listen to the class."

Guan Ming's ears were also red. He looked at the podium and then at his side, took a deep breath, picked up the pen and continued to write the questions.

The classroom was filled up one after another, and the people who came in later noticed that Lin Qianshu had actually sat next to Guan Ming. Although they didn't dare to stare at Lin Qianshu, they mostly looked at Guan Ming twice more, making the original Guan Ming, who was concentrating on the problem, felt uncomfortable. After trying to concentrate for a few minutes, he put down the fountain pen in frustration.

The bell rang at the right time, and the already weak conversation in the classroom completely disappeared.

Jiang Yizhi stood on the podium, with both hands steady on both sides of the podium and looked at the students below the podium: "The biggest difference between the competition and the regular exam lies in the difficulty of the questions. If you want to answer as many questions as possible in a short time , the optimal solution is reduction.”

Lin Qianshu frowned when he heard it in the audience - can this drawing of a turtle help solve math problems?He felt that Jiang Yizhi on the stage was like a Feng Shui master who was bluffing and deceitful. Fortunately, the group of future mathematics elites in the audience listened attentively.

"Transforming the problem you are facing to solve into the problem you have solved is a process of thinking transformation—that is, asking one more question." Jiang Yizhi wrote a sample question on the blackboard, "For example, in this question, It is known that x1 is greater than or equal to 0, and the title requires proof that x1 is less than or equal to 1 plus a, which is actually exploring the relationship between a and 0..."

Jiang Yizhi wrote quickly on the blackboard, a piece of chalk rattled, Lin Qianshu could keep up at first, he just lowered his head and rubbed his eyes, then when he raised his head again, everything on the blackboard suddenly became obscure It's hard to understand.

Why did x2x3 suddenly pop up?Where did the square on their heads come from?Lin Qianshu rubbed his eyes again in disbelief, and found that nothing on the blackboard had changed.He couldn't help muttering: What about teaching turtle painting?So far, even the head of a turtle has never appeared.

Lin Qianshu thought about it, and couldn't help taking a peek at Guan Ming next to him. He was pushing his glasses, writing vigorously, and nodding his head from time to time, as if he agreed with Jiang Yixing's point of view.

With such a hot gaze around him, it was hard for Guan Ming not to feel it. At first he endured it for a while, but soon he couldn't help but turned his head away, and asked Lin Qianshu bluntly, "Mr. Lin, I'm bothering you." Yet?"

Lin Qianshu looked at his notebook full of writing, and asked him, "Do you understand everything?"

Guan Ming's spirit shivered, and he thought that Teacher Lin came to sit next to me today to investigate and understand the teaching progress.He nodded seriously and replied: "Teacher Jiang explained very carefully, and the sample questions are selected according to our acceptance level, so there is nothing we don't understand."

The sincerity written on the young man's face made Lin Qianshu, who was originally planning to seek a "companion that he didn't understand", start to doubt life.He couldn't help asking again: "Jiang Yizhi said he would teach you to draw turtles, but now he finds messy examples for you to do, aren't you disappointed?"

Guan Ming blinked blankly: "Isn't this just a sample question of transformation?"

The two of them stared at each other for a while, and Lin Qianshu realized that he had said the wrong thing again.

Seeing Guan Ming's suspicious expression but not daring to speak, Lin Qianshu laughed awkwardly: "Teacher, I'm just kidding you."

Guan Ming had a face of "So should I laugh at this moment?" He grinned hard to respond to Lin Qianshu, so the two people who had stared at each other just now turned into looking at each other and smiling. It's indescribably weird.

"Guan Ming."

Guan Ming was concentrating on giggling, when he suddenly heard Mr. Jiang calling his name on the podium, and turned his head when he heard the sound, only to see the frightening Demon King Jiang looking at him with a cold expression.Shocked by the cold, he quickly stood up and stammered, "Teacher Jiang!"

"Listen to the class carefully." Jiang Yizhi tapped the blackboard with chalk, and said lightly, "Sit down."

Although Jiang Yizhi didn't say anything serious, after Guan Ming sat down, he never dared to turn his head around and pick on Lin Qianshu.

As a kind and sensible scumbag, Lin Qianshu deeply understood the truth that if he didn't understand, he couldn't influence other people's lectures, so he could only play with his pen in depression.

On the podium, Jiang Yizhi observed that the two people in the corner of the audience stopped talking, looked away, and returned their attention to the blackboard.

Jiang Yizhi stopped after explaining three sample questions. He distributed the papers he had prepared early in the morning, and said to everyone: "The papers for the last class have been entrusted to the monitor. If you are all right, you can try this one. If you have any doubts ask yourself."

Lin Qianshu felt that this arrangement was quite reasonable, at least he didn't have to go up to the podium to say anything.Just as he was thinking, he suddenly saw a group of people standing up with a "crash" and surrounded his table in an instant.

The leader was a girl. She put a corrected paper in front of Lin Qianshu, pointed to a circled question and asked him: "Mr. Lin, since f(x) is a strictly increasing function here, why is the whole rectangle Points cannot include 0?"

Is there any difference between strict and non-strict increasing functions?The function now draws a square instead of a turtle?Lin Qianshu was dumbfounded. He felt as if he was wearing Xinshou village equipment and pretending to be an NPC in the master arena.

Seeing that Lin Qianshu hadn't answered for a long time, the one behind the girl in the row patted her on the shoulder impatiently: "Your question must be too simple for Mr. Lin to answer, so hurry up and I'll tell you why later—" ——" As he said, he folded the paper in his hand on top of the girl's paper: "Mr. Lin, look at me! Why can't the transformation order of the fourth-order magic square be changed? I calculated and the answer seems to be the same ah?"

Lin Qianshu continued to be dumbfounded. The dense rows of numbers danced in front of his eyes. If there was another suona sound in his ears, he could send himself away by himself.

"And I……"

"And I……"

The noise was endless, and Lin Qianshu suddenly heard the sound of heaven while he was dizzy.

"Mr. Lin is not feeling well today, and I will answer all the questions in last week's paper." Jiang Yizhi, who was standing on the podium, said.

As soon as Jiang Yizhi's voice came out, the lively classroom became quiet again.All the students who crowded beside Lin Qianshu took their papers and lined up to the edge of the podium with a somewhat fearful expression.

The girl who took the lead in asking questions to Lin Qianshu was still the one who took the lead. She cautiously said to Jiang Yizhi: "Mr. Jiang, last week's Q&A class was taught by Mr. Lin, and this paper was also graded by him..."

"I know," Jiang Yizhi said calmly, "but I have approved the papers, and I know where you are wrong."

He looked at the girl and said to her: "Wang Siyu, f(x) is a strictly increasing function and has nothing to do with the position of the rectangle. Your mistake is that you omitted +1 in the second step of calculation, so you still can't get a." position." Then he looked at the boy behind the girl: "Lang Xianda, read the definition of the magic square in the question stem."

Jiang Yizhi called the past one by one, and accurately pointed out everyone's questions in the paper, and there was no one whose name and mistake could not be matched. Within 3 minutes, the long line that had been lined up beside the podium was emptied. Everyone grabbed the papers and returned to their seats ashamedly, continuing to fight against their mistakes with bitterness and hatred on their faces.

Lin Qianshu was dumbfounded - before crossing, he had attended school for at least ten years, but there was never a teacher like Jiang Yizhi when answering questions. If a problem can be solved with one sentence, he would never waste a second sentence. And the students who are seeking knowledge are also trembling, it seems that they dare not resist or get used to such a model.

Guan Ming didn't ask any questions, he was already biting his pen and started working on the paper that was just handed out.

Lin Qianshu had nothing to do, so he went to chat with Guan Ming again: "Are you okay?"

Guan Ming raised his head from the paper, shook his head, and a trace of confusion flashed in his eyes: "The paper last week was quite simple, and I didn't encounter any problems when I did it." Why do we have so many questions.

Come on, it turns out that this guy with blue glasses is still a top student.Lin Qianshu sighed, remembering that he praised Jiang Yizhi just now for his easy-to-understand and clear-cut class, which probably had something to do with his own clever little mind.

"But Jiang Yizhi said that, can everyone really understand it?" Lin Qianshu couldn't help muttering in a low voice.

The young man sitting in the front row probably heard the teacher's complaints in the back row. He glanced at the podium and found that Jiang Yizhi, who was standing on the podium, had disappeared at some point. He seized the time to turn around and talk to Lin Qianshu: " Teacher Jiang is okay in class, but when it comes to answering questions, Teacher Jiang is really no match for you."

With a bitter expression on his face, he handed back the paper that had just been sprayed at Jiang Yizhi's place to Lin Qianshu: "Mr. Jiang's lecture speed is too fast, and everyone can't keep up. It's Mr. Lin who is going to explain step by step like this." The steps are suitable for beginners like us who are new to the competition."

"Mr. Lin," the young man tried to impress Lin Qianshu's heart with his bright eyes, "Just give me the lecture topic!"

Lin Qianshu felt an indescribable joy in hearing others praise him, even boasting that he was better than Jiang Yizhi.But he also understands that today's forcing him is destined to be unable to pretend.He sighed, covered his forehead with his right hand after exhausting all his acting skills, and hissed softly: "Oh, my head hurts again... No, no, I feel dizzy after reading the text today!"

A burst of hot water vapor passed from the ear to the back of the hand and finally stopped at the table. There was a steaming cup of boiling water on Lin Qianshu's table.

The teenager who saw the person coming in advance had already quickly rolled up the paper and slipped back to his seat.

Jiang Yizhi put down the water glass, lowered his head and met the confused Lin Qianshu's eyes: "If you have a headache, drink some hot water."

He walked to the front row, took the paper from the boy who was trying to narrow his sense of existence, browsed carefully, spread the paper on the desk, pulled off the pen cap with one hand, and wrote a line on the paper with a pen Formula: "Try this formula to solve it."

The young man took the pen suspiciously, and tried to use the formula Jiang Yizhi just wrote down. At first, his movements seemed hesitant and sluggish, and then he went faster and faster. Finally, he put down the pen and said in an excited voice: " The answer is 6!"

"Well, that's right." Jiang Yizhi nodded, still unable to hear the excitement in his voice, "Use this formula when you encounter such problems in the future." After finishing speaking, he returned to the podium.

Lin Qianshu touched the body of the cup, which was slightly hot, his thoughts were a little messy - did Jiang Yi know that he was trying to save himself?

The author has something to say: Have you returned today?

No update tomorrow, because there is an important job to do tomorrow_(:з」∠)_

The end of the semester is coming, and my next update time may be unstable, Sao Arui, Dogeza