The moment Teacher Lian stepped into the classroom, in fact, Lu Xiqing had already hatched this trick of "killing people with a knife".

Who asked You He Xuan to brag about Haikou just now?

Since you don't think these math problems are anything, go on stage and do it!

It's not good for a bad student to pretend to be forced, but he uses the title to pretend to be forced, so let you perform well in front of everyone!

"Who is He Xuan?"

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

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

Regarding Lu Xiqing's behavior, Dong Zijin is very disdainful.

"That's what He Xuan deserves, Zijin, you also heard it just now...... He Xuan said so smugly that the problem of mathematics or something was nothing to him. This time, it's no wonder to others. ”

Ma Yuanyuan gloated and seemed to be waiting to see He Xuan make a fool of himself.

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

was frightened away by Zhang Haoran just now, and Lu Xiqing was now with Teacher Lian's presence, and the villain's face could be said to be undoubtedly revealed.

"Xuanzi, ignore him. I want to punish you by using the teacher, and wait until school ends...... I don't beat his out. Zhang Haoran squinted his eyes and said viciously.

However, at this time, He Xuan glanced at the question on the blackboard, then stood up with a smile, and said very calmly: "Yo! ”

"You're He Xuan? Okay! If you know how to do it, come up and try it." ”

Teacher Lian nodded slightly, but his mouth was still strange, "Why don't I remember that there is such a classmate in your class?"

Just when He Xuan walked up to the podium to do the question, Lu Xiqing still felt that He Xuan was slapping his swollen face and becoming fat, so he 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. However, recently, our teacher Qin asked the class leader to help him in his studies, and he studied hard in order to pursue our class leader, which must have been fruitful, otherwise he would not dare to say such things. ”

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

Therefore, he thought that his words were a hammer blow, which could make Teacher Lian's impression and attitude towards He Xuan even worse.

However......

To his surprise, when he heard this, even the corners of the teacher's mouth curled slightly, and he said approvingly: "This is very good! You are now high school students, and you are not serious about anything you talk about, but ...... If you can really be angry for the girl you like, and become an excellent person by studying hard, I think ...... It's very meaningful!"

"I'll go!"

Lu Xiqing didn't expect his words to ...... It actually had the opposite effect, how could even the old man appreciate He Xuanlai.

Similarly, hearing Lu Xiqing's words, Dong Zijin's heart shook like a thunderbolt from a sunny day.

"He Xuan is studying hard for me?"

"Usually all his words and actions to deal with me, are they deliberately done to show me? secretly, desperately trying?"

"Impossible, isn't it? His grades are so bad, where does he look like he's working hard?"

"But, the cloze he did today, the answer is almost all right, what can I say?"

"And now, why did He Xuan dare to come up to do this question? This question...... The difficulty is really not low, can he really make it?"

......

All of a sudden, 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 very good grades, and they made a lot of efforts, all of them wanted to please and pursue Dong Zijin.

However, in the face of these, Dong Zijin was unmoved, feeling that these boys were very naïve.

But now she is facing He Xuan, if she ...... A poor student like He Xuan really studied hard for himself, so what kind of motivation should he have for him!

But there is another point, Dong Zijin can't understand very much, why he is so impatient and disgusted when he usually supervises He Xuan's homework and study?

......

At the corner of Dong Zijin's cranky thinking, He Xuan had already picked up the chalk and began to answer questions on the blackboard.

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

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

∵ function f(x) has no extremum,

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

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

......

Brush Brush Brush ......

Twenty or thirty lines of formulas and proofs appear on the blackboard line by line as quickly as printing.

He Xuan's movements were so fast that he didn't even look back as if he didn't need to think, and he didn't even look back at them after writing the formulas line by line.

Brush Brush Brush ......

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, who was at the end of the crane in the class, become so powerful?

This type of question is often used as the finale of college entrance examination mathematics!

Even if it is a scholar like Dong Zijin, he has to review the question for a few minutes before he dares to write and answer, and when he solves the question, he ...... It's also good to check and check it repeatedly!

But He Xuan is good this time, he doesn't even need to type drafts and calculations, and directly prints the standard answers line by line.

Smack!

After writing the last line "This can be proven", He Xuan threw the remaining chalk head into the chalk box very chicly.

Then turning around, He Xuan smiled slightly, and said to Teacher Lian very modestly: "Teacher, do you see what I did right?"

"Yes, yes, yes...... Exactly! Every step is standard and concise, especially the inequality proof at the end. He Xuan, when I saw you doing it, you didn't even think about it, how could you do it so quickly?"

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

When I wrote the first question, I had already figured out how the last question would prove it. However, this type of math problem is the same, there is no difficulty at all, and there are several ways to solve the problem back and forth, which is quite simple......"

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

But what he just said was like an echo, constantly echoing in the minds of all his classmates.

"It's a simple ......"

"Simple ......"

"Single ......"

"The ......"

“......”