This Question Has Been Taught 12 Times Chapter 2

Loop4(2)

Bai Tong is not crazy.Except for being unusual when getting along with her mother Bai Jingru, at other times, in general, she just has a cold personality.

When she came to school the next day, she came earlier and looked in the classroom, but she didn’t see the two classmates from yesterday.

After finishing her morning self-study, she looked back and saw Sun Daining.

I had a good plan yesterday, teaching people how to write questions and so on.But now Bai Tong discovered on the spot that she seemed to have overestimated her interpersonal skills and didn’t know how to speak. Fortunately, Sun Daining came over first.

“Hello, Xueba, I’m sorry for yesterday. I made this for you myself.” Sun Daining handed over a box of blueberry yogurt in a glass bowl.

Before Bai Tong picked it up, Sun Daining seemed to be afraid that she would reject it, so she put it on Bai Tong’s desk.

Bai Tong reached out and moved the bowl half a circle and said, “If you want to learn the question yesterday, I can teach you.”

“What happened to your hand?” Sun Daining noticed the wound on Bai Tong’s hand.

Bai Tong raised his hand. The scratches were a little red, more obvious than yesterday, but no one noticed except Sun Daining.

Sun Daining said, “Isn’t this something you did when you fell down yesterday?”

Bai Tong gave a compromise answer, “Maybe.”

Sun Daining didn’t finish her apology, and then another one came. She said “I’m sorry” again, and then walked back to her seat silently.

Bai Tong didn’t think it was anything. This kind of minor injury would heal on its own in a few days.She looked at the bowl of yogurt through the transparent glass. The milky white semi-solidified solid was sprinkled with blueberries, nuts, and baked oats.There is a spoon wrapped in a napkin on the lid of the bowl. When you open it, the handle of the spoon is a cute little bear.

Bai Tong wrapped it again and put it into his desk along with the yogurt bowl.

At the end of the second period, Sun Daining came over with some medicines. She said to Bai Tong, “Let me help you take care of it.” Then she took out the cotton swabs and iodophor, picked up Bai Tong’s hand and helped her clean the wound.

The classmate next to me saw it and asked, “What’s wrong with the top student?”

Sun Daining thought Bai Tong would answer her, but Bai Tong didn’t, so Sun Daining said, “I accidentally fell.”

The classmate looked at it and said, “This is not that good.”

Sun Daining asked her, “Can’t you see anything?”

“What did you see? How small is this wound? Is it the kind that will heal if you don’t take care of it?”

Sun Daining said with a smile, “It’s very small.”

So the classmate next to me looked at it again, but there was nothing interesting to see, and finally left.

After applying iodophor, Sun Daining covered the wound with a piece of gauze and stuck it with medical tape. She said to Bai Tong, “It will heal faster this way.”

“They don’t seem to be able to see the wound,” Bai Tong said.

“Yeah.” Sun Daining responded.

“But you can see it.” Bai Tong said again.

Sun Daining didn’t know how to answer. She did have some information to share with Bai Tong, but she was afraid that Bai Tong would regard her as a madman.

So he changed the subject and said, “Yin Yi didn’t hurt you on purpose. Don’t blame her. I’ll ask her to apologize to you another day.”

Then he explained, “Don’t let the gauze get wet. If you don’t like it, you can remove it tonight.”

Bai Tong felt that her whole person was very gentle, whether it was the voice she spoke or the actions she had taken when dealing with the wound. Overall, he had a good impression of her, so he asked again, “Topic?”

Sun Daining said, “Forget it, you said yesterday that I can’t learn it. In fact, I don’t think I can learn it, so forget it.”

Uh-oh.Bai Tong felt that what he said yesterday was indeed harsh, so he tried to redeem himself, “I shouldn’t have said that yesterday. Anyway, if you want to learn, you can come to me.”

Sun Daining looked at Bai Tong and smiled and said, “You are indeed a very, very good person.”

When she said this, Bai Tong felt a little embarrassed and looked away.

Sun Daining said, “Do you have time after school today? Can you come to my house to teach me? I have something to go back to.”

Bai Tong suddenly felt that she had just praised him like that just to make it difficult for him to refuse?Now, as expected, he couldn’t refuse and agreed, “Okay.”

When school was over in the afternoon, Bai Tong followed Sun Daining home.They live in the same community, but this community is large and has many doors. They didn’t go through the same door before, so Bai Tong didn’t notice such a classmate in the community.

Bai Tong can usually go home an hour late after school, but now he can still stay with Sun Daining for more than half an hour.

She stood at the entrance with some restraint. Sun Daining said, “It’s okay. You can just come in. There is no one in my house.”

Bai Tong followed in, and Sun Daining explained, “My mother is on a business trip, and she is often not at home.”

After entering, he found that Sun Daining’s house was of a different type. It was a flat floor and quite large. The decoration was in warm wood tones. Bai Tong liked it very much at first sight. It was much prettier than his own home’s marble, crystal chandelier and hotel lobby-style decoration.

Bai Tong has a good habit of washing his hands before entering the house, and then washing the yogurt bowl after washing his hands.

Sun Daining saw it and said, “Let me wash it, your hands are not healed yet.”

Bai Tong said, “It doesn’t matter” and just washed it there with one hand.

Sun Daining didn’t fight with her. She went to the table to clean up for a while, brought a large container of yogurt, put it in the refrigerator, and said, “It seems that it has been fermented too much. It might be very sour. Do you still want to eat it?”

Bai Tong said, “I thought when you said ‘make it yourself’, you meant buying yogurt and adding blueberries and nuts yourself.”

Sun Daining said with a smile, “I grew the blueberries myself, but I bought the nuts.” She pointed out the blueberry plant on the balcony to Bai Tong.

Bai Tong was very impressed. After washing the dishes, he went to the balcony to watch it for a while.

Because Sun Daining was not satisfied with the yogurt, she stopped making it for Bai Tong. Instead, she poured two glasses of juice, took some snacks from the refrigerator, put them on the desk, and started school.

The question is as follows: Given the function f(x) = ln[x/(2-x)]+ax+b(x-1)^3, the first question is, if b = 0, and f'(x) >= 0, find the minimum value of a.

In fact, the first question is not difficult. It is probably to first derive the derivative of f(x), then obtain an inequality about a based on f'(x) >= 0, and finally find the minimum value of a under the condition that its constant holds true.

In the first step, Bai Tong explained, “Because ln[x/(2-x)] appears in the question stem, so 0<x<2."

Sun Daining started to ask, "Why?"

Bai Tong: "…"

Bai Tong: "This is the definition, In(x), x must be greater than 0, so x/(2-x) must be greater than 0. If you solve the inequality, you can get 0<x<2."

Just this thing that could be seen at a glance, Bai Tong talked about it for at least half an hour, and Sun Daining finally reluctantly accepted 0<x<2.

The next step of deriving the derivation was even more difficult for Sun Daining, and for Bai Tong, it was much more difficult than her independent solution to the third question.

After talking for another half hour, Sun Daining still had no clue, and Bai Tong still made no progress. All Bai Tong's patience evaporated, and he was only 100% impatient with the person in front of him, almost to the point of overflowing.

Say it truthfully, "If you really don't understand it at all, I don't think you really need to write this question."

I felt it was a bit much, so I took it back a little further and said, "Maybe you can write the simple ones first, and you can get at least 90 points."

"I don't want to be like this," Sun Daining said pitifully, "No one is worse than me. I must learn this question before the end of the semester."

Bai Tong waited for her to continue explaining, but she stopped here.

"Can I ask why?" Bai Tong is usually not very curious about other people's affairs, but he is a little different about Sun Daining.

Sun Daining looked at Bai Tong and said, "No."

Bai Tong raised his eyebrows to express acceptance.

Look at the time and say, "I'm going home."

"Then can you come again tomorrow?" Sun Daining took Bai Tong's arm.

"I don't think it makes any sense. It will just be a waste of each other's time." Bai Tong spoke very straightforwardly.

Sun Daining thought about it and said, "Actually, I can tell you why I have to learn this question, but I don't think you will believe me."

She leaned closer and said, "You said you would believe me, and I'll tell you why."

This distance was a bit too close for Bai Tong and it felt weird. Bai Tong took a step back and said, "You speak first."

Sun Daining already had a premonition that Bai Tong might not believe her, but she still said it, "Time is circulating."

"The beginning is this question, the end is this question."

"I thought if I could do it, maybe I could break out of this cycle."

After a moment of silence, Bai Tong asked, "What do you mean?"

Sun Daining had an expression of "I thought you could understand it" and explained, "In short, this derivative question appeared once in the opening exam, which is now. When the semester was about to end, the teacher brought a set of joint examination papers from other schools.This question will appear again.At that time, the teacher will ask someone who understands to write the solution process on the blackboard. When you finish writing, the time will be reset to the beginning of the exam, and it will cycle between the two endpoints."

"So you want to learn this question, and then you can write it and see if you can break the cycle?" Bai Tong understood this time.

"Yeah, yeah." Sun Daining nodded fiercely.

"What if you can't learn?" Bai Tong poured cold water on her.

Unexpectedly, Sun Daining said, "Then there is nothing I can do. Even suicide is of no use. I think this cycle should be related to you. Maybe I can only try to kill you."

It's a little scary to hear someone say "I want to try to kill you" to your face, even if the person who says it speaks in a gentle tone.

Bai Tong's response was: "Then try it. You can kill me now."

"…" Sun Daining was a little embarrassed. She didn't know whether Bai Tong was joking or serious, so she said, "It's not that easy. If I say that I am not a real person, can you kill me now? Are you so easy to do it?"

Maybe what she said was true, maybe what she said was false.

Maybe she was the one who went crazy, or maybe she was the one who went crazy.

No matter what the possibility was, Bai Tong didn't want to dwell on it anymore. She twitched her arm slightly and said, "I'm going home."