At the same table, he is manic-depressed, and needs to be spoiled.

Jiang Nuanxing humbly asked for advice, "Then what method should I use?"

Jiang Jinyan didn't tell her right away, but put aside the draft paper on which he had written the answer, and ticked off the original formula on the test paper, "Look at this formula again to see what's there Features."

Jiang Nuanxing knew that her deskmate was going to teach her how to solve problems, so she didn't dare to neglect and began to think seriously.

"You also asked for the guidance of the first question, and you got a few extreme points. You can contact these few to see."

Jiang Nuanxing sketched out a few numbers and calculated them on the draft paper. Jiang Jinyan didn't urge her, but let her think slowly.

Five minutes later, Jiang Nuanxing was not sure and said, "At the same table, do you want to use the method of derivative scaling?"

Jiang Jinyan thinks that the little girl is still very smart, and she can figure it out, "Well, that's right, look at this e∧x, you can replace it with a logarithmic function ㏒, and use the derivative scaling method to prove the second small problem. "

"Okay, this is so hard to think of." Jiang Nuanxing thought of a way, picked up a pen and began to write the proof steps, "At the same table, help me see if my steps are correct later."

"Ah."

Unknowingly, the afterglow of the setting sun began to fall through the mountain peak, and the sky was getting darker.

Jiang Jinyan looked at his watch, it was almost seven o'clock, and he would send the little girl home later.

Ten minutes later, Jiang Nuanxing showed the steps of solving the problem to Jiang Jinyan. After Jiang Jinyan read it, he took a pen and revised a few places, "The proof here is not rigorous, so I need to add a few more explanations... ..."

Because of the close distance between the two, Jiang Nuanxing really smelled the alcohol on the young man's body. It turned out that it was not an illusion, the tablemate really smelled of alcohol, so... did he drink alcohol?
"Are you listening carefully?" Jiang Jinyan tapped the little girl's head lightly, Jiang Nuanxing looked up at him, "Yes."

"Well, you add what I just said."

"Okay." Jiang Nuanxing has a good memory. She remembered what Jiang Jinyan said just now, and wrote it down in her own problem-solving steps.

"Well, if this type of question comes up in the future, if you do it again, will it?"

"Should be, I'll go back and find a few more types of questions to try." Jiang Nuanxing made a mark on the paper, and wrote this question into his notes when he went back, so that he can review it later.

"Well, yes, in fact, if you learn advanced mathematics in college and then do the derivative questions, it will be very easy, but it doesn't matter, you do it according to the high school teacher, as long as you think of the method, you can get full marks."

High math in college?
Jiang Nuanxing was a little shocked, she stared blankly at the other party, "At the same table, have you studied college courses?"

Jiang Jinyan put on a lazy look, and replied casually, "Well, I have taught myself a little bit."

Jiang Nuanxing was hit by [-] points in her heart. She didn't understand the world of Xueshen, "Is it because you know all the courses in high school, so you only read college courses?"

"Well, I've been bored watching the high school ones for a long time, so I'll just watch the university ones." In fact, Jiang Jinyan didn't say that his knowledge of university software and hardware is already better than most college students.

Bored of self-studying college courses because you know everything?
Jiang Nuanxing smiled wryly, being at the same table... really hurt people invisibly.

Noticing the little girl's head drooping suddenly, Jiang Jinyan couldn't help but reach out and rub it. The little girl trembled all over, and the young man felt her trembling, so he let go of his hand.

"Okay, don't think about it, you can still learn high school knowledge if you don't know college courses. You can memorize a few typical formulas for the derivative scaling method. When you really pass the exam, you can also be confident... If you want Top-notch, you can memorize two more classic formulas, look at what I wrote," Jiang Jinyan wrote down a complicated formula on the scratch paper, "This one is the Taylor expansion formula in college high mathematics... and This is L'Hopital's rule, which can be used in proof questions..."

For half an hour, Jiang Jinyan used his own method to summarize several common derivative typical question types for Jiang Nuanxing, and explained to her several college advanced mathematics knowledge points in an easy-to-understand way, which can be used in derivative Prove on the topic.

The little girl listened more seriously than ever before, because what she said at the same table was easier to understand than the teacher. In just half an hour, it was better than the derivatives she had learned in a few weeks, and she also mastered several complex questions that are common in universities. formula.

Jiang Nuanxing's eyes are full of enthusiasm, she likes to stay with the same table, enjoy this kind of heart-pounding feeling, and it is also full of the atmosphere of the sea of ​​books.

The sky was completely dark, and Jiang Jinyan had almost finished explaining to Jiang Nuanxing at this time, "In the future, this kind of question should not be difficult for you, right?"

Jiang Nuanxing nodded, "Well, I have some ideas about this type of question. Even if I can't get all of them right, I can guarantee 80% of them. Thank you, my deskmate—"

"You don't need to say thank you. Teaching you is something that makes me feel happy and relaxed." Growing up together is also what he has always been looking forward to. His little girl is very smart, and she can do it at a glance.

Jiang Nuanxing smiled, "Jiang Jinyan, has anyone ever told you that you are the most gentle person in the world?" Whenever she couldn't control her heart, she was not satisfied with just calling him at the same table Yes, she likes to call his name, it sounds more intimate that way, just like she likes to call her name at the same table for a reason.

In fact, it would be even better if the tablemate is willing to call her nickname "Xing Xing".

Jiang Nuanxing thought so in her heart, but dared not say it.

The most gentle person?

Jiang Jinyan's eyes dimmed suddenly, are you gentle?

He thought that he was an unfortunate person from birth, his mother died in a car accident because of his father, and Jiang Nongchuan once cursed him, "Jiang Jinyan, you should know that there is no relationship between me and your mother anymore, Your birth was a mistake—”

His birth was a mistake!
This is what his biological father said. At that time, he was only five or six years old. He knew from an early age that he lived in a disharmonious family. His father didn't like him, but it didn't matter. His mother's love was enough for him up.

But even though mother loves him very much, she never said that he is a gentle person.

But now, the little girl standing in front of him, her eyes full of starlight, said to him with a bright smile, "He is the most gentle person in this world!"

At this moment, Jiang Jinyan's crippled heart seemed to be healed. He didn't want to restrain his feelings anymore. The young man stepped forward, stretched out his hand without thinking, and hugged the little girl into his arms, "Jiang Nuanxing, in this world Unfriendly, from now on, you will be my own star!"

Jiang Nuanxing didn't notice it for a while, and was hugged by the young man into his arms. His breath was full of the cold mint smell of the young man, as well as the low-alcohol aroma of wine.

The little girl is dizzy, what... what's going on?Why did the hug she wanted so much come true all of a sudden?Is it because God knows that she likes her deskmate so much, and seeing her cute, can satisfy her?