Looking at Wu Bin's slightly disappointed expression, Gu Ningshan was also very uncomfortable, the reason why she suddenly mentioned the atomic model was because Wu Bin praised her very well just now, so in order to strengthen Wu Bin's impression, she took the initiative to provoke this topic, but she didn't expect it to be only half an hour......

She was taken into the ditch by Wu Bin.

'If you have the formula of gravitation, you can use it!' Why are you so big! Do you know what you call drilling the horns of the bull! ’

But Gu Ningshan couldn't shout, because although the question of how gravity is generated has not been completely solved, there are indeed people who are studying it and have a lot of results, but she has not studied it in depth, so the fact is that she was asked by Wu Bin, which made her very angry!

Song Nanfeng, who was originally watching the excitement, was about to snicker, when he saw Wu Bin's gaze moving towards him, which made him feel unbearable, he didn't want to spend a night discussing this bull's horn problem with Wu Bin.

So he stood up with his plate and said, "Let's leave when you're done, I'll take you to the Glasses Lake at night." ”

Hearing that he was going to visit the lake, Wu Bin immediately lost interest, so he said, "Why don't you go tomorrow?" ”

"Okay, then you're going back to the hotel now?" Song Nanfeng asked.

"No, I'm going to go to the library for a while, I just saw a book that interests me."

Song Nanfeng couldn't laugh or cry after hearing this, although he paid so much attention to Wu Bin because of his love for learning and love to the point of madness, but he came to HKUST for so many days this time, and he couldn't make a decision to come to HKUST after being in the library, after all, he had no advantage over Jingbei!

"I'll go with you." Gu Ningshan drank the last mouthful of porridge that was already cold, wiped her mouth, jumped off the chair and said.

"Okay." Wu Bin nodded, he didn't mind having one more library buddy.

"Then I'll go with you." Ding Yuhai also stood behind the two of them after cleaning up the dinner plate.

Looking at the backs of the three of them, Song Nanfeng touched his chin, nodded and said, "Then you guys go, remember to take care of this junior brother more." ”

"Got it~" The two girls said at the same time.

When they came to the library, the three of them sat down quietly, opened their favorite books and began to study.

"I'm a little hungry, are you going to have a supper?" Ding Yuhai asked the other two in a low voice.

Gu Ningshan raised her head and nodded, indicating her agreement.

Wu Bin whispered: "Go ahead, I'll watch for a while." ”

After listening to this, Gu Ningshan tilted her head and glanced at the cover of the book in Wu Bin's hand.

《INTRODUCTION TO LINEARALGEBRA》

"You also gnaw on this book?"

Gu Ningshan's tone was a little surprised, this book on linear algebra was written by Gilbert Strong of the Massachusetts Institute of Technology, and it was one of the pinnacle of linear algebra textbooks, she had also read it, and it was indeed very comfortable to read, but the boy in front of her ......

"Let's go, go for supper, I've also read this book, I can talk to you about my experience, and I'll help you borrow the book."

As soon as Wu Bin heard this, his buttocks, which originally seemed to be "opposites attracting" from the chair, instantly became "magnetic", closed the book and stood up and nodded to Gu Ningshan.

Leaving the library, Gu Ningshan, who no longer had to speak carefully, asked Wu Bin: "How much have you learned by yourself?" ”

"I didn't study much on my own, mainly because I went to the national team training camp of Peking University this time, and those professors taught us a lot of other things after teaching their own courses, and also recommended a lot of books, including this textbook on linear algebra, so I wanted to take a look after seeing it just now."

"I really want to participate in the physics competition......" Gu Ningshan muttered, and then asked: "By the way, you haven't answered me yet, you can also nibble on this book?" ”

"It's okay, it's really well written, and it's easy enough to understand."

"English is good, but this book is quite unfriendly to people who don't have a lot of vocabulary." Gu Ningshan praised.

"Because one of my teachers told me that if I don't learn English well, I won't be able to access the most cutting-edge knowledge, so I still study English hard."

At this time, Ding Yuhai on the side couldn't help but say, "Aren't you going to discuss what we're going to eat later?" ”

"Everything." Wu Bin and Gu Ningshan said at the same time.

Ding Yuhai sighed and couldn't help but hold his forehead.

After walking a long way after leaving the University of Science and Technology, Wu Bin, who was still discussing linear algebra with Gu Ningshan, suddenly found one thing, that is, there were almost no shops around the University, and it looked depressed.

"Don't you even have a barbecue stall nearby?" Wu Bin asked.

"It'll be there after a little walk." Ding Yuhai replied.

Wu Bin nodded, looked at Gu Ningshan again and asked, "But is it really okay for you to come out so late?" ”

"It's no problem to escape for one night once in a while~ I'll stay at my sister's house at night."

'It's a university, it's free! ’

Although I don't know if this is the correct impression, Wu Bin wrote it down anyway.

As Ding Yuhai said, it didn't take long for Wu Bin to see a food stall around the corner, but it wasn't very lively.

"Come, come, sit inside." The boss who was stir-frying saw Wu Bin and they stopped in front of his stall and immediately greeted him warmly.

"Is that okay?" Ding Yuhai asked Wu Bin.

"Yes." Wu Bin nodded.

"That's it." Ding Yuhai pointed to an empty table in front of him.

As soon as he sat down, Wu Bin couldn't wait to spread out the book that Gu Ningshan had borrowed for him, pointed to a question on it and asked: Why is the last matrix e^At, what is e^At equal to? ”

"I'll take a look" Gu Ningshan leaned over to the book and looked at it, and replied: "e^At, if A is not a diagonal array, then it is not calculated how many powers each element becomes e." If we simply follow the definition, we expand Taylor to the power of e^x into infinite terms, substitute x=At into it, and then look at the situation of each element to define it. ”

"According to Taylor's expansion, then after the expansion, it has nothing to do with the exponential of e, and it all becomes a matrix operation with the variable t, how can this correspond to the answer in the book?"

"Two great geniuses, can't they finish eating well first and then discuss the topic?" Ding Yuhai asked with a smile.

She originally thought that Gu Ningshan was already bookish enough, but she didn't expect that suddenly she would be even more ruthless.

"I'm done with this topic." Wu Bin pointed up a finger at Ding Yuhai.

"Okay...... Then you say, I'll help you order food, is there anything taboo? ”

"No, thank you." After Wu Bin finished speaking, he continued to look at Gu Ningshan and asked: "For example, the third picture here gives the exponential function of the diagonal matrix = the proof of taking the exponent on the diagonal element......"

"I'm done with this topic." Wu Bin pointed up a finger at Ding Yuhai.

"Okay...... Then you say, I'll help you order food, is there anything taboo? ”