All-round mathematician

Chapter 213 Modeling breaks the inertia of thinking

After the freshman ceremony, Su Junan and Pan Zhe's orientation battle was over. Yang Fan knew the final result from their many exciting discussions. Indeed, they deceived several girls into calling and chatting in Fetion, listening to the two singles. The bones are a few ounces lighter.

"Calm down and read hard." Yang Fan shouted many times to bring back the atmosphere.

School has just started, and we are about to enter a sprint stage similar to the college entrance examination. It is impossible not to complain.

The mathematical modeling book was borrowed from a senior alumni, and all three of them started from scratch.

Textbooks are really unpredictable, especially math books, the author often shows off his IQ, and finally, it is obvious, and so on.

"It's too high-end, it's really not down-to-earth, how can people learn?" Su Jun'an complained, "Brother Yang, why don't you wait for you to learn more before preaching?"

"Brother Su, don't you want to make a good impression in front of Dean Jiang?"

Yang Fan despises him. He has a textbook in his left hand and a reference book in his right. He keeps staring at two funny people and playing with his mobile phone. His mind is distracted. He is so tired.

Pan Zhe saw that he seemed to be really looking at him, and he was suddenly surprised: "Brother Yang, have you already mastered the legendary left and right distractions? It's amazing. In terms of talent, it is only the same as Xiaolongnu and Xiaolongnu hundreds of years ago. Zhou Botong can compare with you."

No one has ever seen Mr. Jin's divine sculpture. He draws circles with one hand and squares with the other.

"Hmph." Yang Fan smiled triumphantly, and pretended to be mysterious: "This is the secret skill unlocked by my brother as a master of learning. It is twice as efficient as others. What else can I not do."

If the main consciousness and subconsciousness were involved, Yang Fan was afraid that they wouldn't understand, and the real experiment made something happen, so he admitted half-truth and half-false.

"How did you learn?"

"What about making progress together?"

"Go, go, first draw circles and practice for a few years. I was harmed by Zhou Botong in primary school, and I only activated it after ten years of practice."

Yang Fan put down the two books, but he could read them with his eyes closed. The two of them had dirty minds, so they only read for half an hour, always looking for something to say.

On the four desks put together, I have already bought a dozen reference books on mathematical modeling.There is a private bookstore on the Shuimu campus, and the atmosphere is good. Even the bookstore owner needs to talk about it.

The price of more than a dozen books is more than 300, and the boss generously waived the change, and 302 will be 3 soon, all for the progress of Mizuki.

Is there anything to sing or cry about?

""Mathematical Modeling" Jiang Qiyuan, "Mathematical Modeling Basic Course" Liu Baodong, Mathematical Modeling Methods and Analysis" Mark M.Meerschaert..."

Yang Fan flipped through a book and reported it. Su Jun'an and Pan Zhe looked at it and their hearts sank. It would take 10 days to complete these, how could it be possible.

"No one taught me, Brother Yang, I'm still confused." Pan Zhe said.

"It's not bad, the examples in the modeling book are all right." Yang Fan casually flipped open and pointed to the catalog: "Look, the mathematical model of the amount of rain a person walks in the rain, the optimization problem of a movie theater. How down-to-earth, the so-called The greatness of mathematics can only be reflected in the ordinary."

Su Junan sneered and grabbed the book: "To put it simply, look at the following, the mathematical model of launching a lunar landing body, the differential equation model of infectious diseases, the mathematical model of the lethality of nuclear weapons... That's all. The pure theory behind it is even more perverted. Penalty function method, branch and bound method...are they something we can look at now?"

"Anyway, he used to be one of the top academic masters in the city and the province. His qualifications are too low."

People's hearts are broken and it's hard to lead the team.Yang Fan understands that there is a lack of instructors to lead the team. Now the three of them are not even beginners.

He was hoping that the two buddies in the back could help to look up the information, even if he didn't know where to find the information.

"How about we take a look at the video screen, there should be something there." Yang Fan suggested.

With all his notebooks open, Su Junan nodded and searched directly: "Hey, there really is one. It's an open class by our teacher Xie Jin from Shuimu."

"Ah, I checked. Teacher Xie is the instructor of the Shuimu representative team. There must be some interesting information. Take a good look."

The three stools were pulled into a row and they entered the learning state again.

In the video, a 60-year-old man with a thin face and a gray sweater with a black and white plaid shirt collar exposed.

"It looks like a great intellectual at first glance." Pan Zhezheng praised him.The Mediterranean Sea has brushed the center of the top of the head, rubbing the ground, it must be too much brainpower.

"Old Pan, you are too courageous. He was also the one who taught our third-year modeling class. You must die." Su Junan criticized Pan Zhe a few words, then turned his back and laughed.

"Brother, at his age, with his knowledge, even if you are bald, you will be respected when you go out."

As soon as Yang Fan's words came out, Su Jun'an and Pan Zhe's expressions changed drastically, with admiration and envy in their eyes.

The professor of Mizuki has this background. If he can stay in school, he will really not be wronged in this life.

Professor Xie Jin's open class totaled 21 lessons. The first lesson was the basic concepts of mathematical modeling, which happened to be what the three of them needed. Su Jun'an turned up his voice louder, and Pan Zhe closed the dormitory door.

Yang Fan smiled. The thirst for knowledge has already penetrated into the bones of Chinese students.

The video continued to play. Teacher Xie didn't say anything purely theoretical, but asked a practical question about making dumplings in the north.

"One kilogram of noodles and one kilogram of stuffing, today there is too much stuffing, should I wrap more small ones, or not pack a few larger ones?"

"Surely pack a few more, what's the point?" Northerners have a big appetite, and Su Jun'an couldn't wait to answer.

"It's not the same thing if you have a few big ones, please don't be so picky." Pan Zhe retorted.

Yang Fan's head was full of black lines and he said: "Be serious, brother, are you asking me to talk about dumplings? Teacher Xie is using the extra stuffing to derive mathematical problems."

Yang Fan pondered for a few seconds and turned his brain: "It should be about mathematical knowledge about area and volume."

Pan Zhe nodded in agreement: "Brother Yang is right. In fact, elementary school students can also say this question, and it may be difficult to generalize."

"Look, it's better than learning by ourselves. The knowledge that everyone can understand is the university's knowledge." Su Jun'an said.

Mr. Xie continued the video teaching: "In terms of practicality, of course, it is cost-effective to pack a few more noodles. Here is another problem involved. What should I do if I pack more noodles and it is not enough? Reasonable matching of the relationship between the two is the advice I will talk about today. Model base."

Seeing the big from the small, it is very powerful, and the three of them followed suit.

"Before calculating this problem, we need to exclude the largest variable. Because of habit and industrial production, we need to set the same thickness and shape of the dumpling skin. If we want to add this variable, it is not an undergraduate mathematics concept."

Yang Fan praised: "Sure enough, there is a way to simplify the calculation of numbers. Rationalize first, and then pursue changes."

There are many dumplings in the north, but wontons in the south. If you want to make wontons, the shape is more complicated. People's mood, the size of the palm, and the uniformity of force are all included, which is purely useless.

"The skin is a circle, and the area is set to S. N skins are N times S. V is the volume, that is, NV."

"In the end we have to calculate the number N, which is also the relationship between V and N. The two are actually quantitative analysis."

……

"V is N times the root number of NV. 100 dumplings are packed with one kilogram of stuffing, how many kilograms of stuffing can be packed with 50 dumplings?"

Applying it to practical problems, halfway through the course, Mr. Xie asked a practical question.

"How much?" Pan Zhe knew it well, but asked deliberately.

"What do you think?" Su Jun'an said.

Yang Fan rolled his eyes, pretended to be aggressive when he understood, and directly reported the answer: "The root number is 2. That is 1.4 kilograms."

"Look, mathematics is advanced and popular, it's amazing. If you answer this question habitually, you should...should..."

Su Jun'an was speechless, he only knew the result by directly importing it into the calculation formula, but it was difficult to turn around: "100 dumplings are filled with one kilogram of filling, why is 50 kilograms used for 1.4 dumplings, crazy, Absolute nonsense."

Pan Zhe, who was still proud just now, was dumbfounded, what's going on, shouldn't 50 dumplings be filled with half a catty?

This is common sense in life, what are you doing?
Yang Fan was also confused. The teacher seemed to understand when he explained, why the final conclusion and life philosophy are so different.

The three fellow sufferers could not overcome the inertia of thinking in their lives. Yang Fan clicked on the video to pause and held his chin in thought.

Su Jun'an frantically scratched his hair in distress, and Pan Zhe wandered around in the dormitory, seeing a dead end, definitely a dead end.

"Teacher Xie took a video of the public class, it is impossible to make such a big mistake."

Yang Fan looked at the teacher again. Middle-aged and elderly people have long been familiar with mathematics courses. It is really appalling to have such a low-level mistake.

"what happened?"

He closed his eyes and meditated, and directly used data to simulate human actions in his mind. Mr. Xie's answer was correct.

The dormitory was quiet for a full 10 minutes. When Yang Fan opened his eyes, his pupils were bright, and a smile appeared on his lips: "I see, that's awesome."

Seeing the confidence on his face, the two brothers seemed to have grasped a life-saving straw.

"Brother Yang, do you know?" Pan Zhe said.

"Say it quickly, don't be tricky." Su Jun'an said.

"Back to the original question, one kilogram of noodles and one kilogram of stuffing, if there is too much stuffing today, should I wrap more small ones, or not pack a few larger ones? The answer is that more wrappings make smaller ones, and less wrappings make bigger ones. Some." Yang Fan said.

"Nonsense, who doesn't know. I'm asking you a question of square root 2."

"Yes, 1.4 kilograms. It's inexplicable. Lao Xie is bragging and fooling people."

"The key is the amount of flour, and the rest is up to you." Yang Fan said lazily, it depends on comprehension, so mathematics pays attention to thinking.

"When you understand it, you'll be just getting started."

Yang Fan's face turned red. Mathematical modeling was very interesting.

(End of this chapter)