Chapter 146

Gu Lu stood back on the podium.

He rolled up the cuffs of his shirt and tapped the blackboard with his fingers, "Look forward."

"Although the two solutions of Bi Qi and Bai Yao have different ideas, the results are correct." Gu Lu pointed to the dense mathematical formulas on the blackboard and spoke.

"Next, I'll explain the solutions of these two students in detail."

"Look at the problem-solving steps written by Bi Qi on the left. This is a relatively conventional Taylor expansion solution. The advantage is that it is relatively simple and crude. Just put it into the template for calculation, but there are also disadvantages, that is, the operation is complicated and errors are prone to make mistakes."

"The solution given by Bai Yao on the right is actually not difficult to imagine. Simply put, it is to convert the function in the question into the form of Poisson integrals and perform the solution calculation. The amount of calculation will be slightly less, but not every question developed by Tate can be converted into the form of Poisson integrals. Therefore, the solution is not universal."

Gu Lu picked up the chalk and circled the two formulas, "The solution of Bi Qi is not a big problem, but there are still a few small problems. For example, when discussing |x|<1, this formula and this formula are completely unnecessary."

"Since the Taylor series is in a constant convergence to f(x), we can directly calculate ∫(π, 0)lnx(1-2xcosθx^2)dθ to obtain the result 2ln|x|. Also, here, just replace θ=π-t as a variable, without that trouble."

With Gu Lu's revision, the original answer formula with more than 20 lines has been simplified to more than a dozen lines.

Moreover, Biqi's steps that seemed extremely complicated instantly became concise and clear.

Of course, this is for those students who already read it half-understand it.

As for those classmates who were already confused, they are now even more confused.

Ah? Is this easier? I don’t think so!

Can anyone tell me what the formula of the third step means?

What should I do if I can’t understand it at all?

Shouldn’t I come to Yan University to study in the Department of Mathematics?

Many students doubt themselves.

Zhang Jianyi, who was completely confused, looked at Bi Qi, who listened and nodded frequently, and then looked at Ma Zhengxuan, who looked up at the blackboard from time to time, then lowered his head and quickly recorded something on his laptop. He felt like he was doubting whether they were the same type of people.

"Can you understand?" Zhang asked in confusion.

"Very basic knowledge, why don't you understand?" Bi Qi replied, "Is this difficult?"

Zhang Zhibing: "..."

Boss, I'm upset!

Although everyone previewed in advance.

But for normal people, this question in front of them is probably not something that can be understood and solved by previewing alone.

Zhang Jianyang didn't feel that it was too much for the final exam.

But just now, Bi Qi and Bai Yao came on stage to solve this problem one after another.

And the two of them use two different ideas and two different solutions.

Fancy problem solving methods!

This is not a display of strength, but a sufficient display of skills!

Zhang Jianya once again doubted himself.

Are we... really the same type of people?

Both are students of Yan University and are known as the top student, and their levels are divided into different levels.

Obviously, Bi Qi, Bai Yao and Ma Zhengxuan in their class are among the top ones.

The rest of the people can only look down on them.

But as both academic masters, who would rather be willing to be the queen?

After seeing the strength of Bi Qi and his men, many students in the class had already made up their minds to surpass him.

Anyway, there is still a long time before the final exam.

They have enough time to overtake on the curve.

…………

Gu Lu also considered that only a very small number of students could understand his explanation, so he directly and quickly wrote the last question over.

"Okay, this is the two solutions to this question. It doesn't matter if you don't understand it now, but if you can't do such a question at the end of the period, I'll ask you to talk about it." Gu Lu smiled and looked at everyone below with a calm eyes.

But there were still many people shrinking their necks and nodding in fear.

They had just entered high school and obviously had not yet emerged from their fear of teachers in middle school.

Gu Lu smiled, not caring.

It is a good thing that a teacher has majesty in the minds of students. He did not deliberately ask himself and must get along with the students.

Just as Gu Lu opened the textbook and was about to start the lecture, a male student below suddenly raised his hand and asked, "Teacher, is the solution given by Bai Yao the simplest solution to this question?"

"Are you talking about the fourth question just now?" Gu Lu pointed to the question that had not been erased on the blackboard.

The boy focused his attention, "That's right."

"Is the simplest solution?" Gu Lu shook his head with a smile and replied, "No."

Gu Lu said, "The simplest solution to this question requires only six formulas!"

hiss--!

The sound of gasping downwards sounded.

Six…six formulas!

Such a complex problem, only six formulas can be solved?

Just kidding!

The students stared at each other in disbelief.

I thought that Bai Yao’s eighteen formulas were already concise enough, but in Teacher Gu’s mouth, it seemed that it was not worth mentioning.

Six formulas, what can I do?

Just a function deformation and integral solution are two formulas.

Teacher Gu will not deceive them, right!

"Teacher, can you tell us?" Bai Yao's eyes flashed with a soft voice.

"It's okay to talk about it, but it's probably hard for you to understand." Gu Lu shrugged, turned around and wrote six formulas on the blackboard.

[Suppose g(x) is a single-valued function determined in the area D, and x0∈   D,limg(x)-g(x0)/x-x0 is equal to the finite complex α... It can be obtained, ∫ln(1-2xcosθx^2)dθ=2πln|x|.]

There are six formulas, one is not more, and one is not less.

The students all looked up at the six formulas, looking confused.

What is this?!

Originally, they could understand the steps of Bi Qi and Bai Yao even though they were alive.

But the solution given by Gu Lu is really hard to understand even a line of formulas!

They know every numerical symbol.

But when we are connected, we can only ignore each other. If you don’t know me, I won’t know you anymore.

Not only other classmates, but also Bi Qi and Bai Yao were also completely confused.

Only Ma Zhengxuan touched his chin, looked at the steps written by Gu Lu, and pondered slightly.

On the podium, Gu Lu smiled, "It's normal for you to not understand."

"Because, the knowledge theorem used in it is the content in "Complex Functions"." Gu Lu looked at everyone in the audience with a smile, "That is the course you will learn in your sophomore year."

…………

PS: Today I will post two chapters together.
Chapter completed!