Future library

The power of the Star Warlock mainly comes from three aspects. Talent, star formation, plus various computing abilities acquired through training.

Squares and square roots are the simplest calculations, and naturally they are not difficult for astrologers who rely on this. However, to use verbal calculations to calculate the square root of 1369 (the square value of 37), there are not many shortcuts except the familiarity and sensitivity to numbers. .

In the eyes of young astrologers, a person who memorizes the square of 37 (Note 1) will obviously remember more simple calculation results, and these are the basis for increasing computing power.

Even in the 21st century, those talented mental arithmetic boys first rely on memory and memorize many commonly used formulas and numerical calculation results before they can show their amazing calculation abilities.

By the standards of the 16th century, as a twelve or thirteen-year-old boy, Cheng Jinzhou's performance obviously exceeded the expectations of some gentlemen.

How did they know that Cheng Jinzhou was judging the third digit entirely based on the Pythagorean numbers - if he hadn't read "Elements of Geometry" frequently in recent days, his sensitivity to these numbers would be far inferior to that of mathematics students preparing for exams.

No matter what, Liu Kuang had a great impression of Cheng Jinzhou. The young man who looked thin and frail also had the "demeanor" of a star warlock, and he was also "hardworking". His voice became softer and softer: "It's solved." Soon, that little adjustment packet will indeed be the gift that should be given to you."

It proved that Cheng Jinzhou was not lucky, so he had to give out gifts.

Mother Cheng's face suddenly shone with light.

Just listen to Liu Kuang continue: "Then I'll ask you again."

As he spoke, Liu Kuang swiped casually and instantly drew a standard parabola on the paper a few meters away. He asked, "Have you seen this figure?"

Cheng Jinzhou was still praising the miraculous skills of the Star Warlock, but he suddenly fell into a dilemma. In an era when mathematics was popularized, if anyone drew a big inverted U-shape, people's first reaction would be a parabola, not the letter U that was hit by a Mitsubishi modified car. But in this era, it is really difficult to know the parabola. Difficult.

After a moment, Cheng Jinzhou said hesitantly: "I've seen it before."

"It seems that you have read a lot of books yourself. Children of aristocratic families are different after all." Liu Kuang's words were calm, but the appreciation in his tone could be heard by everyone.

The Cheng family does have a good library, but it doesn't have much content on mathematics and physics.

"We call it a parabola. On both sides of it, draw coordinate axes, which are (0, 0)..." Liu Kuang then talked about the coordinate system, in front of everyone, very quickly, but the content was very complicated. Simple.

For this world, the concept of coordinate systems is already considered one of the cutting-edge. Knowing how to use the coordinate system means that analytic geometry has begun to develop. In many cases, analytic geometry can solve many problems that ordinary geometry cannot solve. Of course, the most important thing about it is that it can be integrated with algebra to quantitatively solve geometric problems—— In practical applications, determining numerical values ​​is often more important than qualitative ones.

Perhaps it was the needs of the Star Warlocks. In this regard, their development was far greater than Cheng Jinzhou expected. It seems that a very low-level star warlock apprentice has considerable knowledge of coordinates.

Liu Kuang talked for three or four minutes, then turned to ask Cheng Jinzhou: "In that case, can you find out what the focus of the line passing through the vertex coordinates is and the parabola?"

It is a very elementary question, but it still involves some equations. In the world where Cheng Jinzhou lives, it is a linear equation of two variables, and the answer was obtained after hundreds of years of development.

Several Star Warlock disciples also stared at Cheng Jinzhou. People who have just started to come into contact with the coordinate system must be confused when faced with similar problems, just like Cheng Jinzhou's fathers in his previous life, even though they received basic education from the Cheng family. , but completely unable to understand the problem about coordinates.

Cheng Jinzhou felt a sense of condescension and the pleasure of being discriminated against. He pretended to be pretentious, weakly tapped on the paper, and casually calculated: "25, 25."

After reading it, I realized that the old man's casual stroke was quite accurate.

Everyone in the Cheng family looked at each other in surprise. The sickly Cheng in their impressions seemed to be very different from the child in front of them. Of course, people don’t think of unrealistic time travel.

Liu Kuang continued to ask questions noncommittally, and soon involved simple functions, but it was obvious that these were a bit too childish for Cheng Jinzhou.

Elementary mathematics, for doctoral students in the 21st century, must be studied thoroughly. Ever since he entered college, Cheng Jinzhou has rarely been so confident.

The inquiry soon turned into a discussion. At the beginning, Cheng Jinzhou was a little too excited. In addition, he didn't know much about the development of mathematics in the Daxia Dynasty. He said a few surprising words. Fortunately, it was not a big deal. It's too much beyond the normal range - or in other words, by the standards of a star warlock, the range of normal people is broad enough.

Time passed quickly, and there was a meal in the middle. When night fell, the Cheng family once again warmly invited Liu Kuang to dinner, but the latter refused after all.

Moreover, in Cheng Jinzhou's expectant eyes, Liu Kuang did not ask for a disciple or any other more valuable request. Although he was extremely satisfied with Cheng Jinzhou himself and said a lot of praise.

While he was scratching his head, Cheng Jinzhou had to admit that trying to repeat the successful path of crossing the crowd still failed.

Even Cheng's mother couldn't hide her disappointment and kept saying, "It doesn't matter, you are still young."

In fact, for children who want to become Star Warlocks, 12 years old is not too young. Official Star Warlocks always have many factors to consider when recruiting apprentices, and luck is one of them. After all, they do not recruit apprentices all year round.

A group of people were waiting, having dinner in the main house with different moods, and then went back to their rooms.

Red and yellow lanterns dimly illuminated the bluestone road. Father Cheng was walking on the left side of Cheng Jinzhou, with his hands behind his back. It's a lot more intimate than usual.

He was more pleased than surprised at Cheng Jinzhou's performance throughout the afternoon. After a moment of silence, he said, "I don't know that you like mathematics and science, but this is a way to go. If you like it, you can ask a few colleagues to send you to the project." city ​​or capital."

Xiangcheng is a top city in the entire south.

Cheng Jinzhou was interested, but he quickly shook his head and said, "My parents are traveling not far away. If I want to go, I'll see."

His mathematics has little to do with this era. Even if it is a good school, it is meaningless.

Perhaps because the first sentence was used well, Father Cheng did not pay attention to Cheng Jinzhou's lazy tone. He nodded slightly and said: "From now on, come to my room to test your homework once every three days. Remember."

Cheng Jinzhou suddenly looked bitter, as if he had been beaten up, and objected strongly: "You are usually busy with official duties..."

"That's it, it's settled." Father Cheng showed his style as the head of the family.

Cheng Jinzhou was helpless. Seeing that his mother seemed unable to object, he settled for the next best thing and said, "I want to do some experiments, and I need to get some food."

"Mathematics and science can be regarded as the right path. It's better not to get involved in other things." Father Cheng said, changing the topic and said: "Don't waste it. Please talk to your mother for details."

Like the scholars and literati in ancient China, Father Cheng only had a carefree life and had a weak concept of money itself.

Speaking of things in the inner house, Mother Cheng pondered for a moment and said: "From now on, in the middle of every month, ask Zhuangzi outside the city to send 50 shi of food over. If you want anything, just tell the housekeeper in advance."

"Okay." After a busy day, Cheng Jinzhou couldn't tell whether he should be disappointed or satisfied after receiving such an answer.

Note 1: 37 is a prime number, and the square and cubic values ​​of prime numbers are usually remembered.