After the rebirth, the boss is slapping the face every day

Chapter 309
Leng Yichen walked to her side, opened the math book on the desk, "You can start to make up from the section you missed."

Mu Ruo'an turned to page 38 and poked hard, "It's here."

She started asking for leave from this class, and mathematics happened to be her headache.

When she was reading, she had a headache, almost all the books were looking at her, not her reading.

This class is the invariance of differential form. Looking at the densely packed yfyf, one of her heads is two big, and her eyes are dazzled.

Leng Yichen looked down at the content of this lesson carefully, his eyes moved quickly, almost reaching ten lines at a glance, and soon, he had finished reading all the content, his thin lips parted slightly, and his deep and magnetic voice sounded, "Differential form invariance, whether u is an independent variable or an intermediate variable, has: dy=f'(u)du. This is called first-order differential form invariance."

"Let the function be: y=f(u), then: if u is an independent variable, then the differential form of the function y=f(u) is: dy=y'du=f'(u)du, if u is The intermediate variable, that is, u=g(x), the function is a compound function, and the independent variable is x, that is, y=f[g(x)], and the derivative of the compound function is: y'=f'[g(x)] g'(x), then, the differential form of the composite function y=f[g(x)] (independent variable is x) is: dy=y'dx=f'[g(x)]g'(x)dx , because u=g(x), g'(x)dx=du, put into the formula: dy=f'(u)du."

He did it almost in one go, brisk and nice. If Mu Ruo'an didn't have a headache, he would definitely be addicted to his nice voice.

Leng Yichen explained to her the origin of the formula and how to decompose it in detail. His way of lecturing is very special, unlike the boring teaching by a math tutor. Mu Ruoan, who had no hope at first, was fascinated by listening to it. The more clearly she heard, after his combing, she felt a sense of enlightenment.

This man is indeed a talented student of returnees. It's a pity that he doesn't teach. The teaching world has lost another genius.

"Do you understand?" The man's unique and pleasant voice sounded above her head, pulling Mu Ruo'an back to her sanity, she nodded, "Understood."

Leng Yichen opened the book with his slender fingertips, pointed to the practice questions on it, "Okay, then you can do these questions yourself."

"Okay." Mu Ruo'an picked up the pencil and was about to start working when there was a knock on the door.

"Brother Yichen, are you in there?" Xia Yuluo's voice came in.

Mu Ruo'an frowned, and put down the pen, "It's her again, what is she doing here again?"

"I'll go take a look." Leng Yichen walked over, opened the door, and saw Xia Yuluo standing outside with a book in his hand.

"What's the matter?" The voice was still indifferent, and the expression was as indifferent as ever.

Xia Yuluo hastily raised the book in his hand in front of him, smiling Yiyi, "Brother Yichen, I don't know how to do a question, can you teach me?"

When Mu Ruo'an heard her words, she immediately understood what she was planning, to rob her of a man, right? No, it was to rob her of a teacher, right?

She stood up and walked over.

"No." Leng Yichen refused very simply.

The smile on Xia Yuluo's face froze in an instant, and he raised his hand in embarrassment, neither closing it nor letting it go, and finally his eyes were red, he lowered his eyelids, pursed his mouth, and said pitifully, "Then why did you teach Ruo'an? "

"Yeah, it's Yuluo." Mu Ruo'an walked over, looked at the book in her hand, and pretended to be surprised, "Yuluo, aren't you No.1 in the whole school? Why do you want Yichen to teach you?" , Could it be that he was jealous because he taught me, so he deliberately came to sabotage us?"

Xia Yuluo was so angry that her teeth itch, but she still maintained a smile on her face, "If you think too much, I really can't do one question."

(End of this chapter)