General Military Office.

The courtyard that received Xiong Wencan is now used to receive important guests, and a maid has been hired to be responsible for cleaning.

Six scholars came today, including Xiao Shixuan, all of whom were math enthusiasts.

Because Xiao Shi was given the title of Doctor of Mathematics, and he also received a salary according to the treatment of the county, everyone knew that Zhao Han attached great importance to mathematics. There are more and more people learning mathematics at the top, and there are more and more people learning mathematics.

It's just that most of the scholars are still at the level of primary school mathematics.

"Mr. Zhao!" The six gentlemen stood up in unison.

Zhao Han smiled and raised his hand: "Sit down." ”

After everyone sat down, they turned their eyes behind Zhao Han, but it was Zhao Zhenfang who followed.

In the middle of the courtyard was a blackboard, around which everyone sat on chairs.

Zhao Han came to the blackboard and said, "You are all leaders in mathematics, and the first thing to do today is to establish a mathematical society." This mathematical society, similar to the literary society, usually communicates and discusses mathematical problems, and publishes a journal "Mathematics" every quarter to publish your recent achievements. This year, the General Military Office allocated 20 taels of silver for the establishment and development of the Mathematics Society. ”

The six of them were quite happy, they all belonged to the outliers among the scholars, but they didn't expect to be so valued by Zhao Han.

"The details of the math meeting, you go down and discuss it slowly," Zhao Han picked up the chalk made of chalk, "Let's talk about two things today, one is logarithm and the other is analytic geometry. ”

As a liberal arts student, Zhao Han has almost forgotten about high mathematics, and he has also forgotten many contents of junior high school and high school.

Analytic geometry is taught in junior high school, and logarithm is the knowledge of the first year of high school. For these two things, Zhao Han only remembered the conceptual foundation, and if he wanted to go deeper, he had to rely on Xiao Shixuan and others to study them.

Zhao Han can't wait, he must come up with the basic concept, otherwise he will not know that the Year of the Monkey will be born in China.

Because logarithmic and analytic geometry are very important, they are key mathematical tools for the development of astronomy, navigation, mechanics, economics, military and other technologies. In other words, it was the development of astronomy, navigation, mechanics, and many other fields that forced the improvement of numerical calculations, which gave rise to logarithmic and analytic geometry in Europe.

Without these two mathematical tools, astronomy, navigation, and mechanics would have reached a bottleneck that would be difficult to break through.

Just this year, Descartes coined the concept of imaginary numbers.

China lagged behind a lot at this time, but the emergence of Zhao Han narrowed the gap. More than 90 years ago, the equal sign appeared in Europe, but it was not popularized until more than 40 years ago. Thirty-six years ago, the greater than and less symbols appeared in Europe; Six years ago, multiplication and division appeared in Europe; This year, Descartes used the root number for the first time.

At least, the mathematicians under Zhao Han used root numbers before European mathematicians.

Also in this year, Descartes founded analytic geometry!

On the blackboard, Zhao Han drew a cross coordinate system, with the abbreviated symbol of "A" on the horizontal column, the abbreviated symbol of "B" on the vertical column, and the intersection marked as "0".

Did you suddenly have an impression?

It's analytic geometry, and it's everywhere hundreds of years later, but it's a novelty now.

As Zhao Han drew with chalk, one stroke at a time, the six scholars were all surprised and delighted, as if the door to a new world had been opened.

The more Zhao Zhenfang listened, the more confused she became, as if the blackboard was written in heaven. She looked at the six people next to her, all of them attentively, as if they could all understand.

Zhao Zhenfang felt that she was so weak that she had to study mathematics hard in the future.

Because she found herself bored, she asked her brother for an errand to do something in the math club. For example, helping to contact members, sorting out research successes, editing the quarterly mathematics journal, and so on.

If she can't even read other people's things, then how can she edit the journal?

In one morning, Zhao Han only talked about the most basic things, mainly because he didn't know how to talk too deeply. He threw down the chalk and said, "Stay and eat, I have official business in the afternoon." Leave! ”

"Congratulations to Mr. Zhao!"

The six of them stood up together, and then no one went to eat, and they all took out their small books and looked through them.

"Do you understand?"

"I understand everything, it's like an initiation."

"In particular, the introduction of this variable is a stroke of genius, and many problems in the past can be solved!"

"Mr. Zhao is really a god!"

“……”

The six of them sighed and began to discuss.

In fact, the content they discussed was all mathematics in the third year of junior high school and the first year of high school, and it was relatively simple among them, and the big questions in the final exam were not qualified enough.

Zhao Zhenfang jumped up and asked, "Second brother, can I learn math from them in the future?" ”

"Yes, if you have something you like to do." Zhao Han said with a smile.

The brother and sister stepped out of the courtyard door, and a guard handed over the letter: "Zongzhen, the peasants of Jianchang Mansion have also risen, and Zhao Bingyuan (Fei Ruhe) asked if he would send troops to take over." ”

Zhao Han didn't care about eating, so he went back to the office first, asked the secretary to write a few orders, signed and sealed them by himself, and sent them out before returning to the inner house.

Jianchang Mansion also has a vassal king, called King Yi, whose ancestor is the sixth son of Zhu Jianshen.

This department is quite famous, so don't toss.

The first Yiwang was very frugal, there were few concubines, and the burial was simple. His eldest son and second son were equally frugal. The eldest son left no heirs, and passed the throne to the second son. The second son had five sons, and he took the initiative to request a reduction of 2,000 Shi Lumi,

But it was these five sons who gave birth to eighty-six grandchildren!

By the time of Chongzhen, King Yi's lineage had forty people at the level of county kings alone, as well as countless generals and lieutenants.

They do have a good reputation, because they never make trouble, but the people of Jianchang Mansion don't think so. Like Raozhou Mansion, there was no whip law here, and Zhang Juzheng couldn't manage Jianchang Mansion when he reformed.

This year, Jianchang Mansion suffered from floods and droughts, and the Nanfeng Sect and bandits revived. The Nanjiang uprising next door was happy, and Fuzhou next door was also building a peasant association, so how could the people of Jianchang Mansion not follow suit?

Now, Nanfeng County is occupied by Esoteric Buddhism, and the capital city is occupied by peasant rebel armies.

The Esoteric Sect also went to Guangchang County to preach, and it will definitely be the number one enemy of the peasant association in the future, and it must be resolutely cracked down on this kind of folk sect!

"Something happened again? I'm just here to eat. Fei Rulan asked with a smile.

Zhao Han said: "There is a mess in Jianchang Mansion, and we must take it in advance, otherwise I don't know how many people will die." ”

Fei Rulan said: "In the morning, Uncle Di and the Ling family came to visit, and they told Fei Chun about family affairs. At the end of the year, I got married, and the dates were chosen. ”

"Where is the bride?" Zhao Han asked casually.

Fei Rulan said with a smile: "I know that you don't like to involve the big family, but you are the daughter of an old master in a village school." I heard that she looks like Zhou Zheng, and she also knows some words, and the female celebrity has also done very well, I don't know how many matchmakers come to the door. ”

"Blessed is that boy." Zhao Han also laughed.

Fei Rulan suddenly said: "Rumei and Zhenfang have also reached the age of marriage, shouldn't they think about it?" ”

Zhao Han shook his head and said: "Don't worry, fifteen or sixteen years old, it's easy to have a difficult birth if you get married too early." ”

"My mother is very anxious, and she is already looking for Rumei's mother-in-law." Fei Rulan said.

Zhao Han smiled bitterly: "Don't think about these things all day long, just find something else to do." ”

Fei Rulan said: "I have something to do." The teachers at the Sweeping Eyebrow Girls' School are all married and talented women, and I often correspond with them and talk about literature and art. ”

Zhao Han thought for a while and said, "If you like it, you can also go to a girls' school to be a teacher." ”

"Can I do it too?" Fei Rulan's eyes were shining.

Zhao Han said: "If you are busy, you can only go for half a day, at home in the morning and as a teacher in the afternoon." ”

"That's great!" Fei Rulan was happy, and immediately cheered, as if she had returned to her girlhood.

Zhao Han always felt that Fei Rulan was a little bored, most of them were idle at home, and it would be good to go out to do things in the future. If you really take over the world in the future, I'm afraid it will be difficult to get out, and you will definitely be opposed by the ministers at that time.

After lunch, Zhao Han hugged Fei Rulan, took a nap for a while, stretched his waist and continued to go to the office.

Before dealing with a few official documents, a secretary sent information: North Korea was cleared.

During the first lunar month, Hwang Tae-gil sent troops to North Korea, all the way to Pyongyang. The king of Joseon was frightened and fled to Namhansan with his eldest son and the hundred officials, leaving the second son to take refuge in Ganghwa Island with the royal family.

The Ming army got the news in February and went to sea to rescue in March, but before the reinforcements arrived, they received the news that North Korea had surrendered to the Qing Dynasty.

This year, there was chaos all over the country, there were bandits everywhere, and the surrender of North Korea did not set off any storms, and it was not until now that Zhao Han received the news.

Zhao Han called Pang Chunlai and Li Banghua and took out the secret letter of North Korea's surrender to the Qing Dynasty.

Pang Chunlai frowned and said, "Da Ming is in danger. ”

"It is necessary to occupy the entire territory of Jiangxi in advance." Li Banghua suggested.

A few years earlier, the Manchus had already subjugated Mongolia, and now they have subjugated Korea. It is equivalent to that there are no constraints on the left and right, and you can attack Daming with all your strength in the future, and it will definitely be fiercer and fiercer every time!

Pang Chunlai and Li Banghua were panicked, afraid that Beijing would not be able to hold on.

In fact, this year's situation is too scary, and most of China has been affected by disasters. The drought in Nanzhili and Zhejiang gave Chongzhen the heaviest blow, and its influence far exceeded that of Zhao Han's uprising in Jiangxi.

The Ming Dynasty pays taxes, all supported by Nanzhili and Zhejiang!

Zhao Han said: "The city of Jianchang was occupied by the rebels, and the county town of Nanfeng was stolen by bandits, and I have ordered the army, officials and peasant associations to start in advance. ”

"It should be so," Li Banghua said, "this year we must take Jianchang Mansion, Fuzhou Mansion, and Ruizhou Mansion." In this way, in the whole of Jiangxi, only Nankang, Jiujiang, and Guangxin are left, and they strive to occupy the entire territory of Jiangxi after the summer harvest next year. ”

"I agree with that." Pang Chunlai immediately agreed.

Pang Chunlai came from Liaodong and knew how ferocious the Tartars were. The surrender of North Korea gave Pang Chunlai a sense of crisis, and he was afraid that one day the Tatars would suddenly capture Beijing.

At that time, if Chongzhen moves south and rules with the Tartars, Jiangxi will become a thorn in the side of the imperial court.

It is necessary to occupy Jiangxi as soon as possible, and then take Fujian, Guangdong, and southern Huguang, so that Chongzhen will definitely not dare to run to the south.