I Just Want to Be a Quiet Top Student

Shen Qi volunteered to come to the stage to solve the problem.

He has studied fractions, from fractions I to fractions III, before coming to Yanda.

Not to mention counting, advanced generation, and solution, which are the basic courses of the first-year mathematics department, Shen Qi has also completed the follow-up professional courses such as complex variable functions, partial differential equations, and topology by himself.

University is not a high school. Here, the sky is high and birds are flying. Those who are capable work harder. If you have the ability and energy, you should learn more. No one will let you learn.

Put Shen Qi and a few outstanding students in the big classroom to receive basic education with other students. The professors may have their own arrangements. Sun Erxiong told Shen Qi that at least in the freshman stage, Shen Qi, you have to Come to the big class to listen to the lectures.

The number score question written by Professor Lu on the blackboard is a bit too much. He is making it difficult for freshmen. This question has gone beyond the scope of basic education, and today's number score lesson is Professor Lu's second session. class.

In universities, especially the highest institutions such as Yanda University and Shuimu University, it is not enough to rely on dozens or hundreds of class hours in the classroom. It's time to burn the incense.

"It's not easy to solve this problem with integrated projection, so we need to use facet projection." Shen Qi sorted out his thoughts again, and wrote his answer on the blackboard.

The equation of S is x^2+y^2=4, which is not a continuous function similar to z=z(x, y), and it is difficult to find the normal vector on the side of S.

If facet projection is used, the projection of the cylindrical surface on the XOY plane is a line, which is actually a circle to be precise, so (z+l)dxdy=0

Next, Shen Qi began to calculate the value of -ydzdx.

Determining the value range of x and z requires drawing. Shen Qi made a plane projection on the blackboard, and finally calculated I=-8π.

Shen Qi put the chalk back into the slot, patted the chalk dust on his hands, and said to Professor Lu: "The solution is complete."

Professor Lu: "Shen Qi, you gave an answer. I won't judge your answer for the time being. Please tell me your thinking."

"Okay." Shen Qi stayed on the podium, where he was a professor.

Professor Lu stood on one side with his hands behind his back.

Boom.

Shen Qi tapped on the blackboard: "y is an odd function that is symmetrical to the XOZ plane of the cylindrical surface x squared plus y squared equal to 4, and the 'Sqian' I wrote here refers to the cylindrical surface x squared plus y squared equals 4 when y is greater than 0 part, so y is equal to the square root of 4 minus x. If I say this, can everyone understand?”

"Well, it makes sense." Zhou Yu'an nodded.

"I think so too." Luo Ji agreed.

"Shen Qi's way of thinking is OK." Cai Qing wrote and drew in his notebook.

Ouye looked at it and said nothing, the result she calculated was exactly the same as Shen Qi, but the calculation method was different.

These people were on the same channel as Shen Qi, and while Shen Qi was answering on the blackboard, they also came up with the answer in their own way.

The other students in the Department of Mathematics were half a beat behind, but after Shen Qi wrote out his solution process, they could roughly understand it after reading it. After all, more than half of the students in the Department of Mathematics were recommended to Yanda through mathematics competitions, and their foundation in mathematics was relatively solid. , when they participated in the Mathematical Golden Autumn Camp last year, they had received the education of Professor Sun Erxiong in advance, and the undergraduate courses of the Department of Mathematics.

From last autumn to this autumn, Shen Qi was not the only one who enriched himself in one year.

Sun Erxiong gave directional suggestions to every student in the Mathematical Golden Autumn Camp.

You can learn a lot of knowledge by yourself in one year, if you really settle down to learn.

"Shen Qi, pause for a moment." Professor Lu interrupted Shen Qi's analysis, and called a student's name: "Zhou Yu'an, analyze and analyze, is Shen Qi right? You don't need to stand up, just sit in your seat and say .”

Zhou Yu'an replied with certainty: "Shen Qi is very right."

"Don't be so general, details, I need details." Professor Lu looked at Zhou Yu'an.

Zhou Yu'an talked eloquently: "Actually, Shen Qi's previous derivation and calculation are all routines. The picture he drew is the highlight. The three-dimensional picture of the second type of surface integral is quite troublesome to draw. Shen Qi simplified the complexity and drew a certain The projection of the plane determined the value range of x and z, and finally calculated that I was equal to -8π. I gave Shen Qi 99 points for this wave of operations, and the remaining one point was not given because I didn’t know whether Shen Qi’s answer Correct, Professor Lu needs to judge."

Professor Lu turned to ask Shen Qi: "Shen Qi, what do you want to say about Zhou Yu'an's comments?"

Shen Qi put his hands on the podium and looked at Zhou Yu'an: "Zhou Yu'an, regarding your comments on me, I will give you 99 points for this operation, and I won't give you the rest because you talk too much nonsense."

"Cut." Zhou Yu'an smiled and made a gesture of "If you don't agree with me, hit me".

The atmosphere in the classroom is very active, and Professor Lu deliberately created this atmosphere. Even the mathematics professors admit that mathematics is a boring course. If a boring course is explained in a boring way, some students will really like it. courses?

"Shen Qi's answer and Zhou Yu'an's comment are all right. Shen Qi's answer is correct, yes, it is -8π." Professor Lu said, and said to Shen Qi after the matter: "Shen Qi, you can return Please give me back my podium."

Shen Qi stepped off the podium and returned to his seat.

Professor Lu returned to his seat and returned to the center of the podium. Boom, he picked up the blackboard eraser and tapped on the blackboard. The place where he tapped was the plane projection drawn by Shen Qi: "Here is the key point, you have to memorize it."

The students of the Department of Mathematics in the audience took pens and notebooks, preparing to memorize key points.

Most of the students in the Department of Science and Engineering Computing looked at a loss, the point? What is the point? Where is the point? Why did the focus suddenly appear? Ah, where am I, who am I and where am I going...

There is no harm without comparison.

The overall foundation of the students in the Department of Mathematics is stronger than that of the Department of Science and Engineering Computing.

In fact, Shufen is a very important course in the Department of Science and Engineering Computing. Shufen is almost a purely applied course, and it is a mathematical calculation tool. It may be that the school has just started, and the students of the Department of Science and Engineering Computing have not yet entered the state.

Professor Lu came up with a question, asked students to answer, asked students to explain their ideas, and then asked other students to make comments.

Let students teach students, so why do you need professors?

Of course, the professor is the one who puts the finishing touches. Professor Lu concluded: "I have already said it in the last class, and now I will emphasize the symmetry of the second type of surface integrals. The law of the function is just the opposite. Can you understand it?"

"If you don't understand very well, students should spend more time thinking about it after class. Most of you have received early education such as Yanda Mathematics Golden Autumn Camp and Winter Camp. Don't tell me that you are these few Geniuses start to touch points."

The students who have never participated in the Yanda training camp are speechless. There are not many of them, and a small number of them have passed the college entrance examination and were admitted to the Yanda School of Mathematics.

This small group of students can be divided into two situations. One is that they voluntarily filled in the mathematics major of Yanda University when filling out their volunteers, and the other is that they got very high scores in the college entrance examination and filled in Yanda University but did not choose mathematics as their first choice. They didn't know why they came to Yanda University in a daze. In two cases, half and half.

Professors sometimes have to make a choice, should they take care of the majority or a small group?

Professor Lu's approach is to take care of the majority.

Therefore, those students who don't understand well can only redouble their efforts to catch up, otherwise they will fall behind, and the further they go, the less they can keep up with the progress of the main force.