Urban Boyfriend System

Chapter 30 I really know this question!

At the moment Teacher Lian stepped into the classroom, Lu Xiqing had actually brewed this trick of "killing with a knife".

Who told you He Xuan to brag about Haikou just now?

Since you think these math problems are nothing, just go on stage and do it!

A poor student is not good at pretending to be bad, but he uses questions to pretend to be compelling. Now let you perform well before everyone!

"He Xuan? Which classmate is it?"

Teacher Lian, who was angry, frowned slightly. After all, he has been teaching in this class for three years, and there are only a few top students who are good at math. He Xuan's name sounds...very strange!

"Lu Xiqing is too much, even the teacher is getting angry! How could he just push He Xuan up like this?"

Dong Zijin was very disdainful of Lu Xiqing's behavior.

"That's what He Xuan deserves, Zi Jin, what you heard just now... He Xuan talked about maths and other problems so eagerly, which is nothing to him. This time! No wonder others."

Ma Yuanyuan was gloating and seemed to be waiting to see He Xuan make a fool of herself.

When Lu Xiqing saw that Teacher Lian was getting serious, he shouted at He Xuan: "He Xuan, Teacher Lian called you! Why didn't you stand up? The math problem... isn't it a problem in front of you? Why is it now?"

Just now, Zhang Haoran was scared back, Lu Xiqing's face can be said to be revealed through the teacher's presence.

"Xuanzi, ignore him. This kid is doing bad things! I want to use Teacher Lian to punish you and wait until school is over...I won't punch his shit out." Zhang Haoran squinted and said viciously.

However, at this time, He Xuan glanced at the topic on the blackboard, then stood up with a smile, and said frankly: "Oh! This question! I really know how to do it."

"You are He Xuan? Good! If you can, come up and try."

Teacher Lian nodded slightly, but still said strangely, "Why don't I remember such a classmate in your class?"

Just as He Xuan stepped onto the podium to do the question, Lu Xiqing still felt that He Xuan was swollen and fat, and continued to add fuel to the fire and said to Teacher Lian: "Teacher Lian, He Xuan's previous grades were very poor. So you may not have any impression of him. But recently, our teacher Qin asked the monitor to help him in his studies. In order to pursue our monitor, he studied desperately. It must be fruitful, otherwise he would not dare to say that. ."

In this remark, Lu Xiqing used an ironic tone, especially when he inadvertently revealed the message "He Xuan is pursuing Dong Zijin". He knew that Teacher Lian was most disgusted with the phenomenon of high school students' premature love.

Therefore, he thought that this remark was a blow, which could make Teacher Lian's impression and attitude towards He Xuan even worse.

however……

Unexpectedly, when he heard this, even the teacher raised his mouth slightly and said approvingly, "That's great! You are now high school students. Anyone who talks about love is not doing business, but...if... I can really work hard for the girl I like, and become a good person by studying hard. I think... is very meaningful!"

"I go!"

Lu Xiqing didn't expect that her own words... actually had a counterproductive effect, why even the old man admired He Xuan instead.

Similarly, hearing Lu Xiqing's words, Dong Zijin's heart was shaken like a bolt from the blue sky.

"He Xuan is studying hard for me?"

"Usually, his words and behaviors that deal with me are deliberately shown to me? Secretly, working hard?"

"Impossible! His grades are so bad, where does he seem to be working hard?"

"But, today he did cloze, and the answer is almost all right, so what do you say?"

"And now, why does He Xuan dare to do this question? This question...the difficulty is really not low,

...

Suddenly, Dong Zijin's heart was really up and down.

In the three years of high school, there were many boys who pursued her, and almost all of them had excellent grades. They made a lot of efforts to please and pursue Dong Zijin.

However, in the face of these, Dong Zijin was not moved at all, feeling that these boys are very naive.

But now she is facing He Xuan. If... a poor student like He Xuan really studies desperately for herself, what kind of motivation should she have for him!

But there is another point that Dong Zijin can't understand. Why is he so impatient and disgusted when he usually urges He Xuan to work and study?

...

At Dong Zijin's cranky stall, He Xuan had already picked up the chalk and started answering questions on the blackboard.

First of all, of course, it is necessary to write a big "solution" gorgeously.

Solution: Find the derivative function, we can get f′(x)=(x^2-ax+1)/x^2

∵The function f(x) has no extreme value,

∴The equation x2-ax+1=0 has no root or unique root on (0, +∞).

∴The equation a=x+1/x has no root or unique root on (0, +∞).

...

Swipe...

The flow of clouds and water is general, with twenty or thirty lines of problem-solving formulas and proof formulas appearing line by line on the blackboard as quickly as printing.

He Xuan's movements were fast, even as if he didn't need to think, he didn't even look back at all after writing the formula line by line.

Swipe...

The whole classroom was silent at this moment, only the sound of the chalk in He Xuan's hand rubbing against the blackboard.

Everyone was stunned!

When did He Xuan at the end of the crane in the class become so powerful?

This type of question is often used as the final math question for the college entrance examination!

Even if it's a scholar like Dong Zijin, he has to examine the question for a few minutes before he dare to write the answer. When solving the question... it's good to repeat the calculation and check!

But He Xuan did a good job. He didn't even need to type drafts and calculations, and printed the standard answers line by line.

Click!

After writing the last line of "this can be proved", He Xuan casually threw the remaining chalk head into the chalk box.

Then turning around, He Xuan smiled slightly, and said to Teacher Lian modestly: "Teacher, see if I did it right?"

"Yes! Yes, yes, yes... completely correct! Every step is very standard and concise, especially the final inequality proof. Student He Xuan, when you do it, I don’t even think about it at all? How can you do that? fast?"

Even the teacher was stunned. He asked himself that even if he did it himself, he had to write a few lines and pause. It was impossible to be as smooth and fast as He Xuan.

"Thinking about it! When I wrote the first question, I had already figured out how to prove the last question. However, this type of mathematics problem is the same, and there is no difficulty at all. There are just a few kinds of questions that come and go. The idea of ​​solving the problem is quite simple..."

After speaking, He Xuan patted the chalk dust on his hands and walked back to his seat.

But what he said just now seemed like an echo, constantly echoing in the minds of all the students.

"It's quite simple..."

"simple……"

"Single..."

"of……"

"..."