This Question Has Been Taught 12 Times Chapter 11

Loop4(11)

In the afternoon of the next day, when it was almost time for the lecture, Bai Tong had to find a reason to go out. It would be impossible to apply directly, but luckily she was prepared.

While Bai Jing came downstairs, Bai Tong was rummaging around in the living room.

Bai Jingru looked at it for a while and asked, “What are you looking for?”

“Mom, do you smell a stink?” Bai Tong lay on his stomach and looked around under the coffee table and sofa.

Bai Jingru also came over and smelled it, as if there was indeed such a strange smell in the air.

She also helped to search, and the kitten also helped to search.

Finally, Bai Tong took the paper tube containing calligraphy and paintings and pulled out a round thing from the corner of the sofa.

A rotten egg that stinks as much as a biochemical weapon.

“It must have been either Xiao Jin or Xiao Bao. I saw the two of them playing with eggs a few days ago,” Bai Tong said.

The two kittens meowed a few times and ran far away to the second floor.

Bai Jingru was about to faint from the smoke. She opened the door for Bai Tong and said, “You should quickly take it and throw it away.”

Plan passes.

As soon as Bai Tong went out, he threw away the garbage and ran towards the school. He only took his student ID card with him, and did not bring any other mobile phones or watches. He hoped that it would take some time for Bai Jingru to find her.

After arriving at the class, she happened to catch the bell for the last class. Bai Tong’s seat was already gone, so she found a seat at the back, about a few people away from Sun Daining.

The students were quite surprised, but they were already in class and didn’t have time to ask anything.

After the teacher came in, she continued her lecture from the previous class. In the middle of the lecture, she suddenly saw Bai Tong and said, “Bai Tong is back?”

The teacher seemed to have just said this casually, which attracted some students to turn their heads and look at Bai Tong. Bai Tong said, “Yeah.” In reply, the class continued.

Everything is normal.

Finally, when we came to the last big question, the teacher said, “We have seen this question before, who still remembers it?”

Bai Tong looked at Sun Daining. She was hesitating whether to raise her hands or not. You know, Sun Daining had never raised her hands since the third grade of elementary school.What torture.

No one responded, so the teacher announced the answer himself, “It was exactly the same as the exam at the beginning of the semester. Let’s see if any students can complete it after one semester. Students who can do it are invited to come forward and come to the podium.”

The scream in the class was so silent that you could hear a pin drop.

Bai Tong looked at Sun Daining, and Sun Daining looked at Bai Tong.

Bai Tong’s eyes conveyed, “Go.”

Sun Daining’s eyes replied, “Ah ah ah ah help.”

The teacher called the name, “Bai Tong?”

The teacher still has high expectations for his favorite student, otherwise he would not blurt out “Bai Tong is back” when he sees her.

When Bai Tong remained silent with the teacher, Sun Daining finally raised his hand and said, “Teacher, I can do it.”

“Okay, then please invite Sun Daining to the podium to write about the problem-solving process.” After the teacher finished speaking, he stepped aside and gave the podium to Sun Daining.

As Sun Daining walked towards the stage, she felt her legs shaking.

My psychological quality was not so bad before.Sun Daining considers herself a calm person, and her only advantage is that she remains calm in times of crisis.

Why is it said to be the “only advantage”?

Because she feels that she is very ordinary and has no strengths. She is not as fast as Yin Yi. She has a strong and optimistic personality and an average IQ. Compared with Bai Tong, she can’t even touch her.

But she is calm and easily accepts that she is an ordinary person. Although she is attracted to people like Bai Tong who shined in her student days, she can also accept it as normal if others turn a blind eye to her.

Just look at people from a distance and don’t ask for anything.

Indifferently, be a transparent person.

This is how Sun Daining handles her heartbeat.

No wonder Bai Tong had been her classmate for several years and had no impression of her at all.

But now even the only advantage is gone, and I can no longer remain calm. What kind of things will life force me to do?

After such a short walk, Sun Daining finally finished walking after thinking about it. She picked up the white chalk on the podium and turned to face the blackboard.

“It doesn’t matter, I’ll do it,” she said to herself.

Derivation, solving inequalities, function symmetry, a=-2, derivation again, and discussing the value range of b.

f'(x) = (x-1)^2[2/x(2-x)+3b]

It is known that 2/x(2-x) >=2, so [2/x(2-x)+3b] >=2+3b

Here the dictation begins.

If b>=-2/3, then 2+3b>=0, f'(x)>= 0, then f(x) increases within the domain, f(1)=-2.If and only if 1 is less than x and less than 2, f(x) is greater than -2, which is consistent with the meaning of the question.

If b<-2/3, let f'(x) = 0, then…

I remember that it has three roots. I can’t remember whether it is 1+2/3b or 1-2/3b.

No matter, just guess one, 1+2/3b

Then the three roots are, x_1=1-√(1+2/3b), x_2=1, x_3=1+√(1+2/3b). When 1<x<1+√(1+2 3b), f'(x)="" <="" 0, then f(x) decreases in the domain, so f(x)<="" f(1)="-2, which does not meet the meaning of the question.

To sum up, b>=-2/3

Finished!Look at the teacher first.

The teacher said, "Not bad, Sun Daining."

Sun Daining was relieved, and only then felt that her head was starting to feel dizzy.

But unexpectedly, this is not over yet.

The teacher said, "Third question, tell me your thoughts."

Sun Daining could only pick up the chalk that he had put down.

Sure enough, people can't open champagne at halftime. My head was getting dizzy and I couldn't think at all. I just stood there awkwardly holding a piece of chalk.

The teacher prompted, “Draw the picture first."

Draw a picture?

How to draw.

Sun Daining really couldn't draw. Even if she could think smoothly, she couldn't draw. In the end, she drew a completely wrong one while covering her face.

The teacher looked at her strangely. She didn't dare to look at the teacher or her classmates, let alone look for Bai Tong in the crowd.

In that kind of mood, it's really better to just crash to death like this.

The teacher finally said kindly, "Classmate Dai Ning's spirit is still worthy of encouragement, but her understanding needs to be strengthened. If you have the opportunity to encounter this question again, I hope you will really do it."

"You go down and I'll tell you."After the teacher finished speaking, he erased the picture drawn by Sun Daining, and then started from the beginning with her writing on the blackboard.

Sun Daining didn't know how she got back to her seat. Why didn't time stop? It would be great if time could stop here.

School ended soon after, and Bai Tong was the first to come to her and pulled her out.

They came to the playground, where there were huge stands and many equipment storage rooms.

Bai Tong found a gap between the outer wall of the stands and a temporary storage room, and she and Sun Daining got in together.

The space here is very small, just enough for the two of them to squeeze in. If they had not confirmed the target location and searched, they would not have been found.

Sun Daining felt that maybe in a few days the two of them would be on the social news, similar to children crawling around and getting stuck in walls.Although in fact they are not that young.

Sun Daining and Bai Tong were sitting here huddled together and said, "It's so embarrassing."

"Well, indeed." Bai Tong said.

Sun Daining: "…"

Bai Tong asked her, "When will this cycle end?""

"I don't know. In the past, it usually ended after you finished writing and speaking."Sun Daining said.

“Would that mean that you have actually broken the cycle?Bai Tong asked.

"Really?"Sun Daining looked a little happy, but essentially, she couldn't believe it, nor did she believe that the cycle could be broken so easily.

"Then let's go out and look for someone, shall we?If you were outside the circulation, the scars on your body would probably be visible to others."Although Bai Tong has no scars on his body now, Sun Daining doesn't mind letting Bai Tong make a small sacrifice for the great cause.

"I don't want to go out." Bai Tong said.

"Oh."Sun Daining said.

Sun Daining continued to sit here with Bai Tong. She knew that she was "accompanying" because Bai Tong might really want to stay here forever, but after spending this time with him, she would definitely go out.

"Your mother, why on earth do you do that?"

Sun Daining had never asked this question before, because she felt that it was Bai Tong's privacy and it was not convenient to ask. It might not be convenient for others to ask, but now that she asked, it felt like it was nothing.

“If only I knew.Bai Tong said, "Don't you think many things have no reason?"It's like you can't solve that question."

“I can’t do it because I’m too stupid."Sun Daining said.

Bai Tong said, “You’re not stupid, you’re just not good at it."

"The reason is that I'm not good at it. There's always a reason."

Bai Tong didn't quite agree with what Sun Daining said, but he didn't refute it.

Sun Daining also stayed silent for a while, took out her phone and took a look. It was only after six o'clock.

It gets dark early in winter and the temperature gradually drops. Sun Daining feels that her whole legs and buttocks are numb. She doesn't know how long she can persist here like this pointlessly.

She sat until she felt sleepy, then leaned on Bai Tong's shoulder and fell asleep.

When she woke up, it was so dark that she couldn't see her fingers, which almost frightened her. She quickly pushed Bai Tong next to her, but luckily Bai Tong was still there and said, "What's wrong with you? I'm here.""

Sun Daining said, "Can we go home? I want to go home."

Bai Tong agreed to Sun Daining, and the two of them helped each other stand up from the gap and walked out.

Not far away, a big light on the playground lit up with a bang.

Then came the second, third…

Until the world lights up.