Um, this... Green's function?

Chapter 31: Um, this... Green's function?

The beautiful teacher Wang Lili paused for a moment before speaking, "Hmm... today I will teach you some knowledge regarding mathematical physics equations. Of course, not the homogeneous equations we've covered in class, but rather..."

"Today, our focus will be: the Green's function method for the two-dimensional Laplace equation..."

As soon as these words left her lips, a chorus of groans erupted.

Ye Kaifu finally understood why the first three rows were empty.

This course was absolutely explosive!

The final problems on standard math exams—things like Fourier transforms, orthogonal expansions, and ordinary differential equations—had become mere basic tools here. How could it not be difficult?

Without further ado, the teacher began the formal lecture.

"Students, I trust you have all studied homogeneous and non-homogeneous partial differential equations. Due to time constraints, I will not be reviewing them here..."

Ye Kaifu habitually glanced at Zhang Yuan, only to find that this genius was still lost in his own world, wondering what he could possibly be thinking about.

Wait a second.

He seemed to be asleep!

Asleep, he was actually asleep!

Haha!

Ye Kaifu almost laughed out loud. Seeing that he had gained the upper hand in "diligence," he felt an indescribable sense of satisfaction; he nearly exploded with joy right there in his seat.

Diligence, diligence! I can't slack off just because he's sleeping!

I have to take this opportunity to learn more.

"Most current textbooks use the three-dimensional Laplace equation as the background for establishing the Green's function method. Its core content is the Green's formula in spatial form and the analytical representation of three-dimensional harmonic functions. The Green's function method for two-dimensional problems has similarities to the three-dimensional case... %@@!"

The material was clearly difficult, and even a high level of attractiveness could not directly boost the intelligence of the male animals in the room. As a result, the classroom atmosphere remained awkward, akin to a pretty girl talking to herself on stage.

The foundation of the Green's function method lay in double and triple integrals. Ye Kaifu racked his brain, only to find that he had long since forgotten most of it, forcing him to skip over parts of the lecture from time to time.

Eventually, after skipping enough, he had no idea what the teacher was talking about.

He simply gave up on trying to understand, but since he didn't dare play on his phone in the front row, he decided that admiring the teacher's beauty was a decent alternative.

Good heavens... I finally understand why the boss was too lazy to teach this course and sent me instead.

This is truly torture!

Seeing pair after pair of blank, bewildered eyes, a group of guys burying their heads to nap, and the occasional loser playing on his phone, Wang Lili, standing in front of the blackboard, couldn't stop complaining to herself.

This is exactly like lecturing a bunch of pigs...

She seemed to have forgotten that she had been exactly the same way back in the day. Her own teachers must have viewed her as a pig, too.

Hold it in, hold it in!

I can't take it anymore, this is so frustrating!

Wang Lili, after all, did not possess the broad-mindedness of an old professor who could continue chanting scriptures while a sea of students played on their phones and napped.

She was also very annoyed. I worked so hard to prepare this lesson, and you guys are just messing around down there?

Why? Expecting me to chant like a nun on stage? This princess can't do it...

Hmm, I'll just call on a few people to liven up the classroom atmosphere. It'll be good to wake up the sleepers, too!

That's it!

This boy in the first row looks quite serious, and since he sat in the front row from the start, the probability of him being a top student is extremely high.

He should be able to answer the question. I'll pick him; it won't cause anyone to lose face, and it will wake up the people sleeping.

"This student, please come up and solve this problem!" Wang Lili suddenly said with a smile.

The atmosphere in the entire classroom turned solemn instantly. "Calling on someone" was truly the nuclear weapon of the classroom; almost all the sleeping students suddenly fell from heaven and quickly returned to the mortal realm.

Those playing on their phones also shoved them back into their pockets...

"What? Me?" Ye Kaifu stood up, his face flushed red.

He had been pretending to study hard, only to be called upon to answer a question.

How miserable.

Truly.

"This student, first consider..." Wang Lili offered a few small hints.

"Um, this... Green's function... two-dimensional Green's function..." Ye Kaifu said weakly.

Aside from those few words, he didn't seem to know anything else.

He kept scratching his head and ears, his brain churning violently.

Unfortunately, even if his head were to explode, he wouldn't be able to solve this problem.

"Sigh, sit down, sit down..." Wang Lili hadn't expected that even a good student in the front row couldn't answer, so she could only wave her hand in frustration.

Perhaps she had explained it too poorly, or perhaps the content was just too difficult...

However, the classroom atmosphere had improved quite a bit.

After that little episode, everyone else had adjusted their posture, except for a few stubborn holdouts who were still fast asleep—and I mean truly, deeply asleep.

Especially the one on the far left of the first row; how could he be sleeping so comfortably? Sleeping in the front row was a terrible influence!

"Does anyone know how to solve this problem? Just follow the method I mentioned earlier, using harmonic functions..." Wang Lili reiterated.

The classroom atmosphere became awkward for a moment.

"How about this... student on the far left?"

Ye Kaifu hurriedly patted Zhang Yuan, who was fast asleep, causing him to jump out of his seat with an "Ah!"

What was going on?

Zhang Yuan opened his eyes in a daze.

A small ripple of laughter broke out in the classroom.

"The teacher is asking you to solve the problem!" Ye Kaifu, sitting beside him, winked and gestured, clearly enjoying the spectacle.

Zhang Yuan blushed and scratched his head in embarrassment.

Due to working himself to the bone and suffering from extreme fatigue, he had accidentally fallen asleep.

"This student, do you know how to solve it?"

Although she was a bit annoyed, Wang Lili was prepared to let the student sit back down; waking him up was enough.

Everyone here was an adult responsible for their own life, so there was no need to overly criticize or lecture others.

Besides, this was just a course arranged by the school for various competitions, with no exams or binding requirements...

Zhang Yuan glanced at the PPT, and his groggy brain began to clear. He whispered, "It should be solved using the Green's function..."

Everyone burst into laughter. They had been talking about the Green's function for the entire class; even a pig would have remembered those four words. It turned out this guy had slept through the whole lesson and could only repeat those words.

Zhang Yuan paused for only two seconds before continuing: "Let v be another known harmonic function on the plane D. By Green's formula, we have 0=∫∫(v∂u/∂n-u∂v/∂n)dδ. Subtracting the two equations, we get... considering the boundary conditions..."

"￥@...%￥"

A few top students pricked up their ears, vaguely understanding what he was talking about.

Thinking it over, it actually seemed correct; he wasn't just spouting nonsense.

If someone could spout nonsense at this level, then that would be truly impressive...

Whispers began to ripple through the classroom.

What was going on?

A sleeping guy had just wiped the floor with all of them!