Chapter 8

It’s Wednesday evening self-study, and it’s Gu Lu’s turn to be on duty today.

The evening self-study time for senior high school students is from 7 pm to 10 pm, and there are three self-study classes in total.

In the first and second year of high school, evening self-study is assigned to teachers of various subjects. Moreover, due to the tight teaching tasks, the situation of giving regular classes in evening self-study often occurs.

But in the third year of high school, in order to give students more time to do so alone, evening self-study becomes just a simple self-study time.

As long as you don’t do things that have nothing to do with your studies, you can control these three hours at your disposal.

"I'm in the math group office downstairs. If you encounter any problems or questions you don't know, you can come to me. Also, don't make small moves, I will come here to browse from time to time."

After explaining this to the students in Class 18, Gu Lu returned to the Mathematics Group Office.

I will continue to write that academic paper after get off work tomorrow, so Gu Lu plans to complete the questions of the weekly test papers to be tested this evening.

Ten multiple-choice questions and five fill-in-the-blank questions are the questions that Gu Lu wants to give.

Sitting in front of the computer, Gu Lu pondered for a few seconds, then put his finger on the keyboard and typed the question.

Since it is a test question specially designed for key classes, the difficulty must not be equivalent to that of ordinary questions.

After searching in his mind, Gu Lu already had an idea.

【1, Suppose the complex number z and w satisfies |z|=3,(zw:)(z:-w)=74i, where i is an imaginary unit, z:,w: represents the conjugated complex number of z and w, then the modulus of (z2w:)(z:-2w) is ()

A.√42  B.√65.C.√71D.3………]

[2. Suppose the function f(x)=sin^4(kx/10)cos^4(kx/10), where k is a positive integer...]

【11, it is known that f(x) is an odd function on R, f(1)=1, and for any x<0, there is f(x/(x-1))=xf(x), then f(1)f(1/100)f(1/2)f(1/99)f(1/3)f(1/98)…f(1/50)f(1/51) is _______]

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"Done!"

Gu Lu looked at the questions he had asked and raised his lips.

Overall, Gu Lu is quite satisfied with these questions.

Gu Lu rubbed his hands, looking forward to the students' evaluation of these questions.

"It should be at least a four-star review." Gu Lu murmured in his heart.

He immediately smiled and shook his head, got up and left the office, preparing to go upstairs to see what is happening in his class.

When he arrived at the door of the classroom in Class 18, Gu Lu put his hand on the door handle and was about to unscrew it, but he seemed to think of something and let go of the hand holding the door handle.

Then he walked softly to the back door of the classroom and pressed his face against the small glass window on the back door.

Gu Lu finally understood why teachers in middle school had the habit of peeping through the back doors and windows.

From this perspective, all the students in the class were almost completely in sight, and no one noticed that there were eyes staring at them at this moment.

The feeling of being taken for granted makes Gu Lu feel very sour and even enjoys it.

To be honest, in middle school, what Gu Lu hated the most was that the teacher observed secretly from the back door.

At that time, Gu Lu was caught by the class teacher many times because he was trying math competition questions in other subjects.

But now, Gu Lu has enjoyed this state of voyeurism.

"Do I live the most annoying way I live?" Gu Lu shrugged with a wry smile, and walked to the front door and walked into the classroom.

Gu Lu went straight to a fat man in the back row, knocked on the table, and looked at him condescendingly, "Take it out, I can see clearly at the back door."

The little fat man hesitated and took out a novel from the hole in the table and handed it to Gu Lu tremblingly.

"Come to me on weekends and have a look."

After saying this, Gu Lu walked up to the podium with the novel.

"Your class teacher probably has told you many times, but I still want to repeat it with you here. Your parents sent you here, not to let you play games and read novels. Since you choose to sit here, you should know what to do and what not to do. You have only one task now, that is, study hard! Try to put other things aside."

"OK, you guys continue to study. I'll sit here for a while and raise my hands if there are questions that need to be answered."

Gu Lu moved a chair, crossed his fingers, and glanced sharply at the bottom.

Several students raised their hands one after another, and Gu Lu walked over to answer their questions one after another.

"...Here, substitute the formula after derivation in the previous step into this equation, and change the form on both sides of the equal sign, and you can get this question done."

"Well, I understand, thank you, teacher!"

What made Gu Lu wonder was that most of the questions asked him were girls, and the questions asked should not be difficult for students in key classes like them.

Before Gu Lu could think, he raised his hands again.

"Student Su Ling, you have a question to ask me too? Tell me, which question is it?" Gu Lu said with a smile.

Gu Lu has an impression of this little girl, Su Ling, the female classmate who came to take photos of him in the morning with a SLR.

Su Ling raised her head and said, "Teacher, can I ask first before talking about the topic? Teacher, is your physics good?"

physics?

Gu Lu chuckled, "It's okay. I have published two SCI papers in the field of physics, mainly studying the direction of condensed matter physics and quantum physics. Uh, okay, I said you may not understand this. You have a physics question to ask, there is no problem with this, give me the question to see."

"Ji, this is the question. The physics teacher is not here now, so I can only trouble you, teacher!" Su Ling pointed at the question on the test paper with his pen tip.

Gu Lu glanced at the question and raised his eyebrows, "The question of the final of last year's CPhO (National Middle School Physics Competition)?"

Su Ling's eyes lit up, "Teacher, do you know CPhO, too?"

Not only do I know, but I am also the first prize for CPhO for three consecutive years!

Gu Lu was too lazy to show off in front of a little girl, but just smiled faintly and did not continue to discuss this issue.

"Let's go back to this question. I've come up with the solution. Let me tell you something. Listen carefully."

"Wow, you always have a way of thinking for such a short time!"

"Nothing fuss." Gu Lu smiled and began to explain the question. "This question is not very difficult, but there are too many conditions given in the question, which makes it difficult for you to use when doing the question."

"Look at the first question, it asks you the distance from the rod to the center of the strike O. This is very simple. If you set the distance from the center of the strike to the axis of the rotation is L. The horizontal external force F and the angular acceleration β acting on the center of the strike are given to you. The dynamic equation of substituting the fixed axis of the rigid body is FL=1/3Ml^2β. In this formula, Ml^2β is..."

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Chapter completed!