After entering the house, Yu Hua went to the mourning hall first. The incense candles were burning on the incense table, and there was a layer of ashes underneath. He respectfully offered three incense sticks, bowed three times in succession, and paid homage to Yu Qinghe according to custom.
There were no relatives or friends to mourn, no funeral banquet arrangements, and Yu Qinghe, who had a military style, repeatedly told Yu Hua to keep everything simple during his lifetime.
After adding incense and performing some etiquette, Yu Hua went to the kitchen, washed the iron pot and Chinese medicine, poured half a pot of ice water, put the Chinese medicine into the pot with cold water, found a Da Zhonghua match, took out one and lit it, and set the earth stove
ignite.
This is the inconvenience of living alone, all tedious things need to be handled by hand.
"Let's read a book."
The flames of the earthen stove were strong, and Yu Hua sneezed when he felt the warmth and shook off a pool of snot. He felt a little bored. The excellent study state last night made people forget to leave. I don't know if I can enter that kind of extremely focused study again today.
state.
If you're bored, just read math.
He did as he was told and stuffed a piece of wood into the stove. Yu Hua got up and went to the bedroom. He picked up the arithmetic textbook and paper and pen tools, returned to the earthen stove, and flipped through the books by the light of the fire.
The progress last night was roughly based on solid geometry. The teaching knowledge points were derived from foreign higher education textbooks translated from Chinese to English. Some of them came from the United Kingdom and some from Princeton. They were basically the same as the weapons and equipment produced by the army at that time. They were rich in styles, but there were no
One is for Chinese mathematicians.
There is no way. In this era, the average level of domestic mathematics is far behind the world's level of mathematics. Even catching up is a luxury, let alone parity.
"One of the axioms of solid geometry: If two points on a straight line are in a plane, then this straight line is in this plane. The second axiom: If there are three points that are not on a straight line, there is and only one plane..." Yu Hua
Turning to the chapter on solid geometry, I silently recited the axioms of solid geometry that I had memorized in the past. The two memories in my mind continued to merge and transformed into the text structure of this era.
He read silently in his mind, and studied when he encountered doubts and puzzles. Yu Hua was happy, and the cold and fever did not seem to affect him.
Can learn!
Gradually, Yu Hua felt a surge of strength, and he once again entered a state of selfless learning. The contents of the arithmetic textbook were easily understood, and the parts that seemed obscure and difficult to understand yesterday became simple and common again.
After watching for a while, Yu Hua encountered a question about the angles formed by straight lines with different faces. EF are the edges AP of the triangular pyramid P-ABC and the midpoint of BC. PC=8, AB=6, EF=5, then straight lines with different faces
What is the angle formed by AB and PC?
This question is of medium difficulty. It was written by a teacher from Latimer Middle School in the UK. Holding a pencil in his right hand and a piece of scratch paper on his lap, he slowly started calculating.
Solution: Take the midpoint G of PB and connect GE and GF.
EF is the midpoint of AP and BC respectively, PC=8, AB=6.
Then GE∥AB, GF∥PC, GE=3, GF=4, the angle formed by the opposite right angle AB and PC is ∠EGF. In △EGF, GE2+GF2=EF is satisfied. Finally, △EFG is a right angle
Triangle, and ∠EGF=90°, that is, the angle formed by the out-of-plane straight line AB and PC is 90°.
"It worked out in one go. It's very simple. Continue." Yu Hua figured it out three times, five divided by two, wiped the runny nose with his hand, and felt a great sense of accomplishment in his heart. He didn't dare to delay, and continued.
study.
Comfortable.
It's so comfortable. This kind of question about the angles formed by straight lines with different surfaces has always been in the state of heaven. Every time Yu Hua saw it, he would feel dizzy. Fortunately, he had a good sleep. Now he did it all at once, and he felt fulfilled.
The feeling is almost overwhelming.
Who can understand the joy of a poor student easily solving the exclusive questions of a top student?
Only Bingkuoluo can compare with it!
"Gulu gulu..."
While lighting the fire, I read the arithmetic textbook. After a while, white steam came out of the big pot. The water inside had boiled, and a faint smell of Chinese medicine overflowed from the side of the pot.
Smelling the smell of traditional Chinese medicine, Yu Hua adjusted the fire intensity to medium, and then continued to read the question. The angles formed by straight lines with different planes belong to the calculation basis of spatial solid geometry. Next, it involves line-surface angles, dihedral angles and point-to-plane angles.
Distance problems and other content are cumbersome and the difficulty of the questions is medium. Most of the textbook test questions are from British and German middle schools.
However, the difficulty of this question is medium in relative terms.
For foreign high school students, these knowledge points involving basic solid geometry are not difficult. For domestic middle school students, these things are equivalent to ghost drawings, and many people have headaches when they see them.
Yu Hua is still good. After being tempered by the tactics of Tihai in later generations, he is not only experienced in hundreds of battles, but at least has rich experience.
"Ah!"
After sneezing, Yu Hua rubbed his hands and became more energetic. The pain of cold and fever did not affect the learning efficiency. As he was immersed in efficient learning, more and more mathematical knowledge points were broken and entered into the depths of the brain.
Storage, at the same time, the encouraged brain becomes more and more excited.
dihedral concept,
Problems related to dihedral angles,
Calculation of distance from point to plane,
The distance problem between two parallel planes,
Find the distance in space using the method of equal volumes,
Straight line distance from different planes,
I boiled a pot of Chinese medicine in the middle, which took two hours. I easily mastered the spatial solid geometry calculations of solid geometry, and thoroughly understood the key points of knowledge that almost cover the entire chapter.
Yu Hua woke up from a state of extreme concentration and selflessness. His head felt a little lack of oxygen. In his right hand was a piece of draft paper filled with mathematical symbols and handwriting. This was already the tenth piece.
"Huh... let's take a break. It seems that this person is not only a bit talented, but also a top student with his learning efficiency. But why does Yu Hua's grades in the class in my memory seem average? It's strange, but according to this progress,
I hope to get a perfect score in mathematics." He closed the textbook, put away the pencil and scratch paper, took a deep breath to relieve the symptoms of hypoxia in his brain, rubbed his somewhat swollen forehead, and felt the mathematical knowledge points in his mind, full of expectations.
Now, with Yu Hua's mathematics level, he is taking the college entrance examination again. He is sure that his level in mathematics is at least around 90 points, with an increase or decrease of no more than five points.
If the score falls by one point, you will have to contact the marking teacher.
Calculated based on the current learning efficiency, I can review the main subjects of mathematics, physics, chemistry and biology in about a month. Chinese and Party literature are a bit of a headache. With my traditional Chinese proficiency, it will take at least two months. English
You also have to schedule it, and you also have to learn Japanese. The more you learn, the better.
In addition, arrangements must be made for Yu Qinghe’s burial.
Yu Hua thought silently, got up and went to the stove, picked up a porcelain basin full of Chinese medicine, poured it into a small bowl, and drank it in one gulp.
After drinking the medicine, Yu Hua was going to go to bed to rest for a while, and then went to work on Yu Qinghe's funeral in the afternoon.
"Dong dong!" At this moment, there were sudden knocks on the door of the house.