Jia Yi walked into the classroom, and casually found a back seat to sit down.

"Jiayi, why did you come to class, it's really rare. ”

Before Jia Yi could sit down, he saw a person squeezing next to him, sitting down next to him, and he looked back and saw that it was Trudy.

"I don't seem to have been in class for about half a month, and I just didn't come to the calculus class, and I also took the rest of the courses one after another. ”

Trudy looked Jiayi up and down: "Haven't you been long enough? ”

Jiayi thought about it carefully, he really rarely came to class recently, and today he was a little dizzy because of the balance module of the flying skateboard, and he was ready to change his brain, and he didn't have anything to do, so he came to class to relax.

At this time, class time had come, and Professor Nawang Linna came in with a thick textbook in his hand.

Rinna looked around the classroom, saw Jia Yi who was sitting at the back of the classroom, smiled at Jia Yi and nodded, and said, "It turned out that it was Jia Yi You came over, came over for guidance?"

Jia Yi was a little embarrassed, and folded his hands slightly to salute, begging for mercy.

Linna shook his head slightly, put down the book in his hand, and said, "I'm not actually talking about you, I'm talking about you." ”

As he spoke, he knocked on the table and tapped his fingers: "Look at you guys who are happy, but if you can have half of Jiayi, forget it, cut it in half, I'll cut it in half and half, how much is left, yes, one-sixteenth, if you can have one-sixteenth level of Jiayi, I will simply go to the church, and when I go to class, I can't even solve a simple linear differential equation, it's just... I don't even know what to say. ”

Originally, the rest of the students below saw Linna and said that Jiayi was still watching the joke, but now they couldn't laugh, and they lowered their heads one after another, not daring to look at Linna on the podium.

Linna said as he tapped his fingers on the table excitedly: "Isn't this more difficult than ancient magic scripts, and more difficult than obscure magic arrays to memorize?" For example, if you memorize one, can you help you remember the second one? If you learn the first spell structure, can you learn the second one immediately? But calculus is different, as long as you master the rules, you can calculate the first problem, you can calculate the second problem, and everything can be calculated by calculation. ”

"Teaching ancient magic is a great beauty, can you compare with her? Jia Yi thought in his heart below, but he still made a look of listening carefully and being taught with an open mind, although it was not him at all.

After training his students, Linna began to take lessons.

Linner was taking a class above, and Jiayi was listening a little absent-mindedly below, but slowly, he was attracted by Linna's class, and today, he actually began to talk about partial differential equations.

It's not the first time for Jia Yi to take Linna's course, and he also has some understanding of Linna's style, I have to say that Linna's level is still very good, Jia Yi feels that he is because of the higher development of mathematics in the previous life, so he takes advantage of the medicine. But when it comes to the solidity of the foundation, he himself may not be able to compare with Linna, so Linna's class, Jiayi can still get a lot of inspiration.

But although Linner has good knowledge, as a teacher, he is not excellent, his progress in class is very chaotic, there is no complete framework, or even if there is, he often thinks of where to say.

This is very demanding for his students, such as Jiayi can keep up, the progress of learning is very fast, listen to the key points a little, pay attention to it, but like Trudy, you will feel very sad, often feel like you are listening to the heavens.

In this case, you can only learn by yourself, the college's requirements for teachers, that is, don't talk nonsense, you can really have a level, and there is really no requirement for the quality of teaching.

After a while, Rinna noticed Jiayi again, and in the whole classroom, there was no confusion on his face.

He only finished talking about ordinary differential equations two days ago, and today he began to talk about partial differentials.

He stretched out his hand and pointed at Jia Yi and said to the rest of the people: "Look at you like this, it seems that I am not speaking the same language as you, let's let Jia Yi come up and talk about it, maybe he is close to your age, which will make it easier for you to understand." ”

As he spoke, he beckoned Jia Yi to come up.

Jia Yi didn't have stage fright, this is not the first time, when the school first started, Jia Yi often came to class, and was pulled up by Lin Na several times, if it wasn't for problem solving, or if it wasn't for explaining ideas, there was even a class with most of it.

After coming to the stage, Jia Yi gestured to Lin Na and said, "I don't know how to talk about it, so I'll come up with a question and explain the idea of the question to everyone." ”

He wanted to choose a topic from Linner's textbook, but suddenly he remembered the skateboard flight control and balance problem he was working on, so he thought about it for a while, ignored a few parameters, simplified the conditions, and idealized it, and came up with the problem.

"There is a quantity accelerating downward, and the normalized n-system gravitational acceleration is rotated to the b-system by the left-hand of the rotation matrix R, i.e., k is the normalized rotation matrix R(b-e)... Finally, we calculate the downward deviation based on this. ”

After Jiayi's title was written, he looked down, but found that everyone's expressions felt a little more confused, and no one's expression was relaxed.

When Trudy went up in Jiayi, he still thought that Jiayi could speak more clearly, and the first few times Jiayi came on stage, both the problem solving and the teaching ideas were very clear, and they were very detailed, and they would not omit some steps that they didn't seem to need, so in Trudy's eyes, Jiayi's teaching level was actually higher.

But when this topic came out, he felt that it was a little difficult for him to even understand the topic, what the hell was this talking about.

Jia Yi didn't have the idea of finding someone to try to solve the problem, so he directly started to solve the problem: "We first construct the target attitude rotation matrix, and then obtain the rotation matrix D of the current state by controlling the quaternion, and take the Z-axis vector in the two matrices, that is, YAW-axis... Calculate the weight of the yaw... Construct e_R_cp antisymmetric matrix, calculate the error of yaw, and further update the error value e..."

Jia Yi said very quickly, brush brush and write fast, the students at the bottom only felt that they couldn't keep up with Jia Yi's train of thought at this time, a little delay, and they couldn't keep up with the progress at all, and the previous detailed solution, and strive to make the classmates understand Jia Yi is completely different, almost all people feel that this Jia Yi is not replaced by another person, after all, this is the magic world, and it is very simple to make an identical person.

After Jia Yi brushed the brush to solve the problem, he felt that he was not addicted, and continued to solve: "Get the current angular velocity value r, calculate the angular velocity difference rates_err, calculate the angular velocity difference rates_err, consider the drifting compensation, and finally get the value required for adjustment." ”

Seeing that Jia Yi had finished solving the problem, Lin Na hurriedly came up to stop Jia Yi, invited him down, and then said: "You should write down this problem, if you can solve this problem independently, then you will have at least the level of the fourth grade, and you will not be far from being a teacher." ”

Linner was a little skeptical that Jia Yi was not intentional, although he usually took classes a little whimsically, but at least he wouldn't be too far away, but Jia Yi's questions and solutions this time were a little too long, and it felt like revenge for always pulling him up to lecture.

However, Jia Yi didn't have the energy to do what he thought at this time, and he, like the others, copied the questions he had just written and the ideas for solving the problems on the notes, and at the same time, he also wrote down some of the experiences he had just learned.

Although this topic simplifies a lot of conditions and idealizes the situation, it does have a great inspiration for his own flight control balance scheme for flying skateboards, which allows him to see the light in the chaos.