"Don't disturb Brother Fan's thinking!" Zhu Xianwen said dissatisfied.
Fan Xiren's forehead tightened even more. He flipped through the book and found that the answer was indeed six.
"Can you understand this book?" Fan Xiren obviously didn't believe it.
Li Yu replied casually: "Of course."
"How did you get the solution to be six?" Fan Xiren obviously still didn't believe it.
"This is not simple. First find the original function of 2x-1, which is x²-x, then substitute 3 and 0 and subtract."
Fan Xiren was silent for a long time before saying, "What is this brother's name?"
"I'm Li Yu."
Zhu Xianwen next to him was confused: "Did he get the answer right?"
Fan Xiren said: "Not only is it right, his solution is also quite concise."
Li Yu was a little embarrassed by what he said, because for him, this was not even a grade-giving question for the first year of high school.
Fan Xiren continued: "My dear Fan Xiren, this is Zhu Xianwen. Both of us are late students who are determined to learn Western learning."
Li Yu hurriedly cupped his hands and said, "You're welcome, sir!"
Fan Xiren looked at Li Yu: "You are here..."
Well, people still can't understand his identity as a "librarian". Li Yu shrugged and said, "When you live in troubled times, there is nothing you can do. You know."
That's all I can say. You can't tell people that you are actually the sweeping monk in the scientific world of the Qing Dynasty!
Fan Xiren seemed to be used to this kind of situation, "I see, it's just... I just didn't understand a few things accidentally. I wonder if you could please teach me a little more?"
"Of course." Li Yu thought to himself. For him, the content of this book is at the introductory stage of advanced mathematics at best. As long as you don't ask about Goldbach's conjecture, everything is easy to explain!
Just as Li Yu thought, Fan Xiren's questions basically revolved around some elementary calculus questions, and many of them were conceptual explanations.
Calculus is one of the most monumental creations in modern mathematics, and modern people have become accustomed to it. However, the ideas and concepts used in it are actually extremely advanced and profound, which will inevitably make these people who only read the Four Books and Five Classics on weekdays. Confused.
Regarding the questions asked by Fan Xiren, Li Yu's answers were very straightforward, but it was a bit troublesome to express the calculus operation in words.
Zhu Xianwen only read it for a while, but he was so confused that he couldn't say a word.
Almost an hour later, Fan Xiren stood up and prepared to leave. He said to Li Yu: "Mr. Great Talent, none of the teachers I have in Ziqiang School are as good as you. If Teacher Hua Hengfang could see you, he would be very good." I hope to have a long talk with you all night long. It’s a pity that I can’t figure it out now, so I’m really sorry.”
Fan Xiren is worthy of being a descendant of Fan Zhongyan. He is polite and has a strong ambition to make progress.
Li Yu said: "Brother Fan is overly praised."
Fan Xiren took out a pocket watch, looked at it, and said, "I have something to do at home. I don't know where your husband lives. I will definitely pay him a visit tomorrow."
Li Yu pointed to the backyard in embarrassment: "I...live here."
Fan Xiren made a long bow: "I'm really wronged, sir! When I see my mentor later, I will definitely recommend him! I'll say goodbye first, and I will definitely come here again tomorrow to ask for advice!"
"Farewell!"
It would indeed be a good thing if he could really introduce Zhang Zhidong. Among the four famous resurgence officials in the late Qing Dynasty, Zhang Xiangshuai was the one with the most advanced ideas. Moreover, he is a very popular minister and has served as a feudal official for a long time, so he has much less resistance to doing some innovative work.
After bidding farewell to Fan Xiren and Zhu Xianwen, it was already getting late. Although there were electric lights in the Tongwen Hall, there was no electricity in the backyard where Li Yu lived.
There was nothing he could do in the dark, and probably because he had just traveled through time, the jet lag hadn't come over yet, and his head hurt, so Li Yu went to bed early. I had a good sleep this time, but the hard bed was not very comfortable.
The next day, just after dawn, the sounds of other handymen working could be heard outside. Li Yu didn't like to sleep in, so he got up and went to the library to continue "working" for a while.
It was almost nine o'clock when the meal started in the backyard kitchen. I went over and took a look: a bowl of porridge and two cakes. The food was really light!
Fortunately, yesterday's head of the Etiquette Department, He Fangxu, kept his promise and sent someone to deliver the wages during dinner.
Looking at the dirty fifty copper coins in his hand, Li Yu didn't expect that his first salary in his life would be the imperial grain of the Qing Dynasty! It’s so memorable!
After spending another half day in the library in the morning, Li Yu finally sorted out the books in various categories. By noon, he was hungry. After asking, he found out that the kitchen only had two meals a day, and dinner would not be opened until four o'clock!
Li Yu was 1.8 meters tall and always loved sports. He couldn't stand it any longer, so he had to go for a walk on the street.
To the north of Dongtiaozi Hutong is Jinyu Hutong. This alley is relatively wide and the streets are clean. Many wealthy households and many princes and ministers live there. The house where Li Hongzhang lived in his later years is in Jinyu Hutong.
There are many stalls in the alley. Of course, those princes and ministers will definitely not squat in front of the stalls to suck noodles. The main customers of these stalls are the maids and servants of the deep houses.
But don’t underestimate them, these people have very strong spending power! Although their wages are also very low, many expenses can be reimbursed by their masters.
Besides, the masters didn't have time to go out and buy things. When they needed something, they just gave the money to the servants and maids and asked them to buy it. The extra money was rewarded directly. Of course, there are also some servants who spend one tael when buying things, and then repay the two taels when they go back. The masters are used to lavishing things, and they don't feel anything at all.
After walking around for a while, Li Yu was attracted by a smell, and there was a stall in front of him that was crowded with people.
"It's done, Dingzi, hurry up and give me a bowl of mutton mixed noodles!"
"And I've been waiting for my soba noodles for a long time!"
The stall owner Dingzi is a young man with very nimble hands and feet. He is serving noodles and shouting:
"A bowl of mixed mutton noodles costs 8 cents!"
"A bowl of soba noodles costs 4 cents!"
Li Yu weighed the huge sum of money in his hand and felt that this was the most suitable one for him!
A servant also came to the stall and said, "Do you have any more cakes to post? The four of us brothers will serve 8 cakes!"
Ding Zi immediately waved his hand: "Master Lin, there are no more pasties today. How about I give you four bowls of noodles?"
"Who said there is no more? You still have a lot in this basket!" Mr. Lin pointed at the basket of cakes next to him and said dissatisfiedly.
Ding Zi said: "Master Lin, these have been decided a long time ago. It's not that I won't give them to you."
The servant was not too happy: "Let's just say it's on a first-come, first-served basis. How about ordering in advance? I want to order this cake!"
Ding Zizheng didn't know how to respond when a sharp voice came from behind: "What's wrong! Our family ordered the pancakes early in the morning. Who said I didn't pay attention to first-come, first-served?"
The servant looked back and his tone immediately softened: "It's Eunuch Wei! How did I know it was you!"
Eunuch Wei didn't want to pay attention to him. He picked up the basket and put down a dozen copper coins. Then he said to Ding Zi, "Deshan, we gave Eunuch De a taste yesterday and he liked it very much."
Li Yu was shocked when he heard this. Ding Deshan, it turns out that the owner of this noodle stall is the founder of the famous Beijing Donglaishun Hotel!
