future library.

Chapter 13 Regular Heptagons

Drawing with ruler and compasses, complete a regular heptadegon!

The others didn't say anything yet, Cheng Jinzhou froze on the spot.

I swear by the doctorate title he got through the back door, this kind of topic is definitely not something the old lady came up with by herself.

Don't think it is easy to make a regular heptagon. Before the 18th century, this was a world-class problem, and it was a very meaningful topic.

These days, Cheng Jinzhou is reading books on geometry every day. Although there are not many books on this kind of book at home, he can also learn about the level of mathematics in this world from the side.

It may be able to reach the level of Europe in the early sixteenth century, and some aspects may still be surpassed, but the study of how to make a regular heptagon - to some extent, has surpassed the limit of this era .

The so-called ruler-compasses drawing refers to the way of making graphics by using only a limited number of rulers and compasses without scales.The limited number of times mentioned here means that the use of trial and error is eliminated.

This is a seemingly simple, but complex proposition.In fact, in Cheng Jinzhou’s history, this proposition was finally solved by Gauss—another amazingly talented mathematician who made countless contributions in his life. The least square method that caused headaches for science and engineering students, And the normal distribution curve, which is often in contact with liberal arts students, belongs to his achievements.As for the most familiar thing about Lord Gauss' wisdom, it may be the calculation problem he completed at the age of ten or nine: 1+2+3+...+100.

In the 21st century, all children who have been exposed to Mathematical Olympiad may not know Gauss, but when you ask "what is the sum from 1 to 100", most of them may not even need to do the math, and just answer "5050".

Cheng Jinzhou has long forgotten how long it took Gauss to study rulers and compasses to solve regular heptagons since he entered the university, but naturally it took longer than 20 minutes. In other words, unless the astrologers of the Great Xia Dynasty Mathematics level, and then advance more than 100 years, otherwise it is absolutely impossible.

Mathematics is a step-by-step process. It is really building a fortress on the sand. It can be unique, but it can never develop by leaps and bounds. A mathematical formula that lacks a step-by-step proof is wrong.

Cheng Jinzhou believes that if the astrologists of the Great Xia Dynasty could generally understand the regular heptagonal ruler and compass construction method and related propositions, then they should have entered the industrial society long ago—this is obviously impossible.

At this time, 20 minutes is meaningless. The old lady should be planning to make the two children unable to answer the questions.

This is a good way, it won't embarrass Long Zizhi too much, and it can be regarded as a safe victory.The only problem is that Cheng Jinzhou is a little upset.

If the old lady hadn't been so shrewd, Cheng Jinzhou would still have been very, very confident in comparing math with a big kid.

Even a Ph.D. in physics produced by cheating will never be weaker than a high school student at the level of the 16th century.

In fact, even if he were to draw a regular heptagon, Cheng Jinzhou would undoubtedly be able to complete it within 20 minutes.

Studying how to draw a regular heptagon and its principles, even in modern times, can be used as a graduation thesis for undergraduates in the Department of Mathematics. However, using the method developed by the research to draw with a ruler and compass is a mid-term exam for junior high school students. .

The problem is that in the eyes of everyone, Cheng Jinzhou does not seem to have the ability to surpass the times.

Dr. Cheng himself has not made similar preparations.

Minutes passed by.

His opponent, Cheng Jinhao, lay down on the table early, trying to come up with an approximate pattern of a regular heptagon. With the level of a 14-year-old child, he obviously did not expect how difficult the problem would be—it required mathematics. The elites have accumulated 200 years of strength before they have the opportunity to succeed.There are too many formulas, theorems and ideas, which must be created and summarized by predecessors.

Cheng Jinzhou knew, so he simply stood by and looked at everyone with a playful mood.

The members of the Cheng family can be said to be the most educated elite group in the world. Each of them has received nine years of compulsory education in the famous Cheng family private school, but faced with a problem beyond their cognition for 9 years, they There is no difference between Cheng Jinhao and 200-year-old Cheng Jinhao.

Most of the people pointed to Cheng Jinzhou and then to Cheng Jinhao with such an expression.Obviously, a child who is doing problems on his stomach is more convincing than a child who voluntarily gives up.

Cheng Jinzhou was very dissatisfied with the different expressions of the bystanders.

Especially when the black robes also used their eyes to locate the "second generation ancestor who didn't work hard", Cheng Jinzhou was furious.

As a former active doctor, Cheng Jinzhou hates people looking at him as a "second generation ancestor who doesn't work hard", even though he has cheated infinitely, he is indeed a disgraceful second generation ancestor...

Without looking at the expressions of Cheng's mother and Cheng's father, Cheng Jinzhou stood up impulsively, pointed at the black robes and said, "Can you do it again?"

"Cheng Jinzhou!" Cheng's father was taken aback for a moment, and then he blushed and became angry.

It's true that the black robes don't even have a one-star rating, but they have the potential to become real star warlocks.In places like the Great Xia Dynasty, they were also recognized as star warlocks.Astromages deserve respect everywhere, at least not by a child scolding them.

Cheng Jinzhou didn't flinch from this, he was never a very rational person, he pointed his thin fingers from left to right, and said: "You have been immersed in astrology for many years, how can you answer this question now? Are you qualified to laugh at me?"

The words were a bit harsh, but in terms of mathematics, Cheng Jinzhou could indeed be proud of the astrologers enshrined by the Cheng family.He proudly said: "There is no solution to this question right now, am I right?"

The gentle questioning made the scene quiet for a while, and Cheng Dazhifu saw that the old lady did not speak, so he simply did not say a word.

The astromancer who asked the first question before continued to stroke his beard, and said indifferently: "I can't answer this question in Xia Wuzong."

Good demeanor, coupled with a distinguished status, was immediately recognized by everyone, and they all said "no problem", and heatedly discussed.This is obviously another topic to show off at the dinner table.

Cheng Jinzhou is not a fuel-efficient lamp, not in the past, not even now, because of his young age, he swayed his fingers and said: "Mr. Wu, you haven't answered my question yet. You can answer that, right?"

"This..." Wu Zong stroked his beard, momentarily at a loss for words, it seemed that it was not easy for him to admit the failure of the astromancer.

Perhaps it was because he was really too young, but instead of stopping his son, the mature and prudent Cheng father stood aside and watched his performance.As a prefect, since the day he took office, he seldom gets along with his growing son.I also want to see how much knowledge and ways of dealing with people have been learned by the children who have been sick all year round.

Cheng Jinzhou didn't give up, turned his head and said to the old lady: "Grandma, I know that there is no solution to this problem, but Cheng Jinhao doesn't know it. From this point of view, although neither of us has finished it, I know more Some, no?"

Cheng Bingxun, who was kind and generous, said without hesitation, "Cheng Jinhao worked hard to complete the inspection, but you rely on a little miscellaneous knowledge and cleverness to steal the victory, so you should be judged to be the loser."

It's shameful for a dignified son to get involved in the games of the younger generation. Now that he is going into battle shirtless, not to mention the people of the Long family, the other members of the Cheng family can't stand it any longer. Someone behind him suddenly said: "Be kind to Cheng Bingxun, Cheng Bingxun who is not worth a dime, Cheng Bingxun is as clean as water..."

Cheng Jinzhou heard of many names for the first time, almost laughed out loud, and only restrained himself when he remembered the gift from Baqing.

The old lady didn't accept Cheng Jinzhou's fault, she smiled gracefully, and said kindly: "Since neither of them can answer the previous question, Jinzhou should go in, after all, he is a grandson."

"After all, he is a grandson" made Mr. Le Shanhao Shi's face turn green and red.

Cheng Jinhao is also a grandson, but the word Long is a bit farther away. If it weren't for his good father, the old lady would not have said that.Now, the father and son can only experience the cruel hierarchical society.

With such an arrangement, Cheng Bingxun couldn't say anything, just watched Cheng Jinzhou answer, and watched Cheng Jinzhou get up and walk out, praying with all his heart.

A small episode, left to the Cheng family, was more of a talking point, and it soon dispersed, leaving only the households with children, waiting to be tainted with the joy of being drawn.

Cheng Jinzhou strode into the bright longhouse.

(End of this chapter)