Urban Shared Boyfriend System

There are only less than 30 days left, and you still think you can counterattack?What kind of self-confidence is this?

"Xiqing, I laughed so hard. Did you hear what He Xuan said just now? He still wants to counterattack? Do you really think he is the arrogant protagonist in the novel?" Lu Xiqing's tablemate Yang Weicheng laughed Said.

"Idiots are dreaming. Anyway, they are bragging and don't need to pay taxes. He really thinks that Teacher Qin will arrange Dong Zijin to help him, and his grades will skyrocket?"

Lu Xiqing said sourly, at the same time, something bad was going on in his heart.

The class bell is ringing, this is math class.

Mathematics teacher Lian Hengxin is an old pedant. He became bald in his 40s and wore gold-rimmed eyes.

Similarly, even the teacher's temper is the most irritable among all the subject teachers, and even physically punishes the students with a pointer.

It can be said that even Dong Zijin, a top student in the eyes of teachers, will inevitably be afraid when facing even the teacher.

The math class is also the only one where He Xuan and Zhang Haoran dare not sleep in class and go to bed, even if it is pretending, they have to pretend to be listening to the class seriously.

"Attend class!"

Holding the lesson plan, put it on the podium with a bang, even the teacher's voice was a little hoarse, it sounded like he was in a bad mood today.

All the students in the class seemed to be hanging on their hearts at this moment. Everyone cheered up 12 points, for fear of accidentally provoking even the teacher to lose his temper.

"Today, let's talk about some typical difficult problems. After a while, these few problems... I hope that some students will take the initiative to solve them on the blackboard..."

He went straight to the topic, and even the teacher wrote a big math problem on the blackboard, and then asked, "This problem is about conic sections, who will do it?"

As soon as Teacher Lian spoke, the class immediately fell silent.

This question is actually not difficult, but because it is Teacher Lian's class, if you accidentally do it wrong... you will be punished and scolded, no one wants to be the first bird.

Even if he did the right thing, did it a little slower, and the steps and thinking of solving the problem were different from his standard answer, he would still be severely criticized.

"Let me come! Teacher Lian..."

After waiting for more than ten seconds, no one raised their hands, so Dong Zijin, the class monitor, had no choice but to volunteer, and then went to the podium to answer the question very neatly and perfectly.

"Have you seen it? Dong Zijin's steps are beautifully written. List out the formula, put the numbers in...the answer will come out, it's very simple, right? So, don't be afraid when you see this type of topic , let alone scare yourself. Carefully analyze what type of question this is, find the applicable formula, and analyze the known conditions..."

Comparing with Dong Zijin's answer, even the teacher explained it for a few minutes with satisfaction, which can be regarded as an analogy for this type of question.

Then, he erased the question again and continued to write the next question on the blackboard.

Known function f(x)=x-1/x-alnx

(1) If f(x) has no extreme value points, find the value range of a;

(2) Let g(x)=x+1/x-(lnx)2, when a takes the maximum value in (1), find the minimum value of g(x);

（3）证明不等式：∑1/√（2i（2i+1））＞ln（2的n+1次方）/（2的n次方+1）（n∈N*）．【注：这里数学符号打不出来，无法完整还原题目，凑合一下！】

Hey!

As soon as this question was written, the whole class gasped.

It can be said that in high school mathematics, this type of function is the most difficult type to find extreme values, maximum values, and minimum values, as well as to prove inequalities.

Some students who are not good at mathematics start to have a headache every time they see a long list of summation formulas and inequalities.

"This question, who will come up and do it?"

After finishing the topic, Teacher Lian glanced down. None of the students in the class dared to look at Teacher Lian!

Everyone quickly lowered their heads. Who would dare to confirm their eyes with Teacher Lian at this time?

"What? No one dares to come up and do it? This question...isn't difficult!"

No one took the initiative, and even the teacher's face darkened.

But just after he finished speaking, Dong Zijin raised his hand again: "Teacher Lian, let me come!"

There was no way, Dong Zijin really didn't want to go up every time, but as the class monitor, in order not to embarrass the teacher and students, she had to go up often by herself.

"Dong Zijin, sit down. You come up every time, what about the other students? Is sitting here empty?"

Seeing that Dong Zijin volunteered again, even the teacher pointed at everyone angrily and scolded, "You...you are really the worst class I have ever taught. You don't even have the courage to come to the stage to do the questions. Is it gone?"

At this time, Lu Xiqing, the deputy monitor, thought it was a good opportunity, so she suddenly raised her hand and stood up and said, "Mr. Lian, let He Xuan go to do it? When class was over just now, I heard He Xuan holding a math problem book Confidently say there, these problems are nothing at all! I think he will definitely do this question..."

……

[Math problem: I am a very difficult math problem!Do you want to conquer me?Secretly tell you, my nemesis is the recommendation ticket.As long as you crazily vote for this book, you can solve any math problems you encounter in the future...]

Chapter 30 I really know this question!

The moment Teacher Lian stepped into the classroom, Lu Xiqing had already planned this trick of "killing someone with a borrowed knife".

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

Since you feel that these math problems are nothing, go on stage and do them!

It's not good for a poor student to pretend to be coercive, but to use the questions to pretend to be coercive. Now I will let you perform well in front of everyone!

"He Xuan? Which classmate is it?"

Teacher Lian, who was getting angry, frowned slightly. After all, he had been teaching this class for three years, and there were only a few top students who were good at math. This 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, Zijin, you heard it just now... He Xuan said so bluntly about math problems, it's nothing to him. This time! No wonder others."

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

Seeing Teacher Lian getting serious, Lu Xiqing yelled at He Xuan: "He Xuan, Teacher Lian called you! Why don't you stand up? Mathematical problems... aren't problems in front of you? Why are you scared now?"

Having been scared away by Zhang Haoran just now, now that Lu Xiqing is with Teacher Lian, that villain's face can be said to be revealed without a doubt.

"Xuanzi, ignore him. This kid is playing tricks! He wants to use Teacher Lian to punish you. Wait until after school... I won't beat his shit out." Zhang Haoran narrowed his eyes and said viciously.

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

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

Teacher Lian nodded slightly, but still asked strangely, "Why don't I remember that there is such a student in your class?"

Just when He Xuan stepped onto the podium to do the questions, Lu Xiqing still felt that He Xuan was slapping his face to make himself fat, so he continued to add fuel to the fire and said to Teacher Lian: "Mr. 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 monitor to help him in his studies. In order to pursue our class monitor, he worked hard to study hard. It must have been fruitful, otherwise he would not have dared to say that. .”