After the freshman ceremony, Su Junan and Pan Zhe's welcome battle ended, and Yang Fan knew from their many excited discussions that the final result was okay, and they were indeed fooled into a few girls' phone calls, and the language chat in Feixin made the two single-born dogs listen to the bones of the ground a few taels.

"Give me a good book. Yang Fan shouted many times, bringing the atmosphere back.

has just started school, and it is impossible to enter a sprint stage similar to the college entrance examination, without complaints.

The mathematical modeling book, borrowed from the alumni of the fourth year, all three started from scratch.

Textbooks are so inscrutable, especially in math books, that the authors often show off their intelligence, and in the end, obviously, and so on.

"It's too high-end, it's really not grounded, how can people learn?" Su Junan 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 despised it, he had textbooks in his left hand, reference books in his right hand, his eyes were still staring at the two teasers and playing with his mobile phone, his mind was scattered, etc., he was tired.

Pan Zhe saw that he seemed to really see the ground, and he was suddenly surprised: "Brother Yang, have you mastered the legendary left and right distractions, and you are so awesome that in terms of talent, Xiaolongnu and Zhou Botong can compare with you hundreds of years ago." ”

Mr. Jin's divine condor, who has never seen it, draws a circle with one hand and a square with the other.

"Hmph. Yang Fan smiled proudly, and pretended to be mysterious: "This is the secret skill unlocked by my brother as a scholar, it is twice as efficient as others, what else can't I do." ”

If it involves the subconscious of the main consciousness, Yang Fan is afraid that they won't understand, and the real experiment will make things happen, and the half-truth and half-truth will admit it.

"How did you learn it?"

"What about making progress together?"

"Go and go, first draw a circle and draw a square to practice for a few years, I was killed by Zhou Botong in elementary school, and it took more than ten years of practice to activate. ”

Yang Fan put down the two books, but he closed his eyes and read them, the two of them were not pure-minded, so they read for half an hour, and they always had nothing to say.

On the four desks put together, a dozen or so mathematical modeling reference books have already been bought. There is a private bookstore on the Mizuki campus, and the atmosphere is so good that even the bookstore owner has to drag articles to communicate.

The price of more than a dozen books is more than 300, and the boss boldly waives the fraction, and 302 is quickly given to 300, all for the progress of Mizuki.

Is there anything to sing and cry about?

"Mathematical Model" Jiang Qiyuan, "Mathematical Modeling Fundamentals" Liu Baodong, "Mathematical Modeling Methods and Analysis" Mark ......"

Yang Fan flipped through a book and reported a copy, Su Junan and Pan Zhe looked at their hearts and sank, how could it be possible to finish these in 10 days.

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

"It's okay, the examples in the modeling book are okay. Yang Fan casually flipped through the table of contents and pointed to the catalog: "Look, the mathematical model of the amount of rain that people walk in the rain, and the optimization problem of the cinema." How down-to-earth, the so-called ordinary can reflect the greatness of mathematics. ”

Su Junan sneered and grabbed the book: "To put it simply, look at the following, the mathematical model of launching the lunar landing object, the differential equation model of infectious diseases, and the mathematical model of the lethality of nuclear weapons...... That's not all, the pure theory is more perverted later, the punishment function method, the branch delimitation method...... Is that what we can watch now?"

"Anyway, I used to be one of the top students in the city and province, but my score was too low. ”

The hearts of the people are scattered, and the team is not easy to lead. Yang Fan understands that there is a lack of instructors to lead the team, and now the three of them are not even beginners.

He was counting on the two buddies behind him to help check the information, but he was afraid that he wouldn't even have a clue where to find the information.

"Otherwise, let's look at the video, there should be. Yang Fan proposed.

The notebooks were all open, Su Junan nodded, and searched directly: "Hey, there really is, it's an open class of our teacher Xie Jin from Shuimu." ”

"Ah, I've checked, Mr. Xie is the instructor of the Mizuki team, there must be dry goods, take a good look. ”

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

The video shows a man in his fifties and sixties, with a thin face, a gray sweater, and a black and white plaid shirt with the collar exposed.

"At first glance, he is a great intellectual. Pan Zhe praised it seriously. The Mediterranean Sea has brushed the center of the top of the head, and it is definitely too much brain power.

"Lao Pan, you are too bold, our junior modeling class, he also talked about it, to die. Su Junan criticized Pan Zhe for a few words, then turned his back and laughed.

"Brother, when he is his age and has his knowledge, even if he is bald, he is respected when he goes out. ”

As soon as Yang Fan's words came out, Su Junan and Pan Zhe's faces changed greatly, and their eyes showed admiration and envy.

Professor Mizuki has this background, if he can stay in school, he will really be unjust in this life.

Professor Xie Jin has a total of 21 public classes, the first lesson is the basic concepts of mathematical modeling, which is exactly what the three of them need, Su Junan turned up his voice louder, and Pan Zhe closed the dormitory door.

Yang Fan smiled, the thirst for knowledge has long been deeply rooted in the bone marrow of Chinese students.

The video continued to play, and Mr. Xie didn't say anything purely theoretical, but asked questions about making dumplings in the north as a practical problem.

"One kilogram of noodles and one kilogram of filling, there are more fillings today, do you pack a few more small points, or a few fewer large ones?"

"There must be a few more, do you need to say this?" The northerners have a big appetite, and Su Junan can't wait to answer.

"It's not the same to pack a few big points, don't pick it so badly. Pan Zhe retorted.

Yang Fan was full of black lines, and said, "Be serious, brother, are you talking about dumplings?" Teacher Xie is deducing math problems for the extra stuffing. ”

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

Pan Zhe nodded in approval: "Brother Yang is right, in fact, primary school students can also say this problem, and it may be almost inductive." ”

"Look, it's better than learning it ourselves, and the knowledge that everyone can understand is the university question. Su Junan said.

Mr. Xie continued: "In terms of practicality, of course, it is cost-effective to pack a few more, but here it involves another problem, what should I do if I have more noodles and not enough? ”

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

"Before calculating this problem, we need to exclude the largest variable. Because of habits, because of industrial production, we have to set the thickness of the dumpling wrappers to the same and the same shape. To include this variable, it is not an undergraduate math concept. ”

Yang Fan praised it vigorously: "Sure enough, there is a doorway to simplify the number of calculations." Rationalize first, then pursue change. ”

There are many dumplings in the north, and there are wontons in the south, and if you want to wrap wontons, the shape is more complex, and the person's mood, the size of the palm, and the uniformity of the force are all counted, which is purely useless.

"The skin is a circle, and the set area is S, which is the volume, that is, NV. ”

"In the end, we have to count the number N, which is also the relationship between V and N. Both are actually quantitative. ”

......

"V is N times the root number of NV. 100 dumplings, wrapping one kilogram of filling, how many kilograms of filling can be wrapped in 50 dumplings?"

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

"How much?" Pan Zhe knew in his heart, but asked deliberately.

"What do you say?" said Su Junan.

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

"Look, math is lofty, popular, and powerful. This question should be answered habitually...... Should ......"

Su Jun settled down and couldn't speak, he only knew the result by directly bringing in the calculation formula, but it was difficult to turn around: "100 dumplings are only wrapped in one kilogram of filling, and 50 are only 1.4 kilograms, neurotic, absolutely nonsense." ”

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

This is common sense in life, what is Nima doing?

Yang Fan is also a mush, and the teacher seems to understand when he explains, why the final conclusion is so different from the concept of life.

The three brothers and sisters couldn't overcome the inertia of thinking in life, Yang Fan clicked on the video to pause, holding his chin and pondering.

Su Junan grabbed his hair in distress, and Pan Zhe walked around the dormitory, a dead end, definitely a dead end.

"Teacher Xie took a video to record the open 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, and it is really appalling to have such a low-level mistake.

"What's going on?"

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

The dormitory was quiet for ten minutes, and when Yang Fan opened his eyes, his pupils were bright, and the corners of his lips hooked up a smile: "I see, awesome." ”

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

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

"Say it quickly, don't sell it. Su Junan said.

"Back to the original question, one kilogram of noodles and one kilogram of filling, today there is more filling, should there be a few more small points, or a few fewer large points? The answer is more foreskin and smaller foreskin, less foreskin and larger foreskin. Yang Fan said.

"Nonsense, who doesn't know. I'm asking you a question about root number 2. ”

"Yes, 1.4 kilograms, inexplicably, Lao Xie is bragging and fooling people. ”

"The key is to ration the flour, and think about the rest. Yang Fan lazily said more, here is to rely on understanding, so mathematics pays attention to thinking.

"When you understand it, you'll be able to get started. ”

Yang Fan's face was flushed, and the mathematical modeling was very interesting.