Xueba, I beg you to go and escort him quickly!

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"Here, CD equals AB+BD."

"And this is actually used as a question in many junior high school exams."

"Come on, pay attention. We have many ways to prove it. There are short-cut methods, truncation methods, and so on."

"Look at them one by one."

"..."

Xu Heng talked a lot.

He didn't follow the topic at all, let alone what the math teacher said!

Xu Heng, "Continue to read the questions."

topic:

What is the smallest fraction of -1.2?

"I see the answer you wrote is -0.2?"

Zhou Xiaoya nodded desperately, "That's right, isn't it?"

Xu Heng said coldly, "No."

Zhou Xiaoya was frustrated on the spot, "Huh? Huh... Then I made a wrong question again? Why? Isn't this question -0.2?"

"Impossible! Brother! Did you lie to me?!"

"This question is so simple! Brother! I'm afraid you are kidding me!"

"Brother! You definitely did it on purpose!"

"Our whole class is -0.2! That must be the correct answer!"

Zhou Xiaoya clenched her jaw and looked at Xu Heng seriously.

Xu Heng rolled his eyes, "This type of question mainly appears in real numbers and quadratic radicals. To be honest, this kind of question is not often tested, but once it is tested, the whole army will be wiped out."

"This question examines the definition of the integer part and the decimal part of a number."

"A number whose integer part is the largest integer not exceeding this number."

"And the fractional part of a number is equal to subtracting the whole number from the number."

"For example, 1.2, the largest integer not exceeding 1.2 should be 1. Subtract the integer part from 1.2, and finally get its fractional part 0.2."

"What about -1.2? What's the integer part of it?"

"Since -1 is greater than -1.2, it exceeds -1.2, so -1 is not its integer part."

After Xu Heng sorted it out, Zhou Xiaoya's questioning eyes gradually changed.

Her struggles were also gone.

She was completely dumbfounded.

"This, this, this... can it still be like this? So the largest integer part of -1.2... is... -2?"

Xu Heng nodded, "Yes."

Zhou Xiaoya, "Oh my god! It's too bloody! This, this, this..."

She frowned, and said it very reluctantly, "So the decimal part of it should be?"

Xu Heng, "Yes."

Zhou Xiaoya, "*%￥#@￥￥......"

She waited for a long time before she came back to her senses.

"Hey……"

Although he didn't want to admit that he was wrong, but Xu Heng had reason and evidence, and he couldn't do it if he didn't admit it.

Xu Heng, "I'll make a list for you, please pay attention to it."

Zhou Xiaoya leaned over.

She thought it was a formula or something, but she never expected that what Xu Heng ordered her was a study task.

"Fifteen days to finish, last year's provincial high school entrance examination questions..."

Zhou Xiaoya's face turned dark, "Brother, brother... Please, you, what are you doing!"

Xu Heng didn't listen to her begging for mercy.

Just get on with the task.

"In addition, I will teach you all the algorithms and calculation ideas that the teacher has not taught."

"I will teach you the butterfly algorithm, nine-point concentric circles, Peto's theorem, Morley's theorem, etc."

Zhou Xiaoya pouted, "Brother...me, can I ask you a question?"

Xu Heng, "???"

"You have a grudge against our teacher!"

Xu Heng, "???"

"What you teach, our teacher seems to have never taught it..."

Xu Heng, "Stop talking nonsense, I'm going back to school on Monday, hurry up, don't waste time."

"I happened to encounter this question, let's take a look at Morley's theorem first."

"Three interior angles of a triangle are divided into three equal parts, and two triangular lines close to a certain side intersect to obtain an intersection point. Then such three intersection points can form an equilateral triangle."

While talking, Xu Heng wrote.

"We now appear to be proving that."

Xu Heng came to pick up a pen:

In △ABC, AQ, AR, BR, BP, CP, CQ are the trisectors of the angles, the lengths of the three sides are a, b, c, and the three interior angles are 3α, 3β, 3γ, then α+β+γ =60.

In △ABC, by the law of sines, AF=csinβ/sin(α+β).

Without loss of generality, if the diameter of the circumscribed circle of △ABC is 1, then by the law of sine, c=sin3γ...

……

Proof is halfway through.

It wasn't that Xu Heng couldn't prove it, but that Xu Heng suddenly thought that Zhou Xiaoya was only in junior high school!

She is just a junior high school student... her knowledge in this area is far from enough, and Xu Heng's proof is beyond the mark for her.

Xu Heng, "%￥#@￥￥%..."

"Hiss... In my head, I keep telling myself that she is only in junior high school, so she must use a simple one, and a simpler one... Hey... Blame me, blame me..."

Xu Heng murmured, then stopped proving, and changed a piece of paper.

Zhou Xiaoya, "Ah? Brother! What's wrong with you? Can't you prove it?"

Xu Heng, "The following proof is out of line, so I'm afraid you won't understand it, so let's use a simpler one."

puff-

Zhou Xiaoya seemed to be hit hard!

The whole person is not good.

Zhou Xiaoya looked at Xu Heng's eyes, very resentful, "*%￥#@#￥......"

In this way, various theorems and problem-solving ideas were presented to Zhou Xiaoya by Xu Heng.

Zhou Xiaoya also learned a lot under Xu Heng's dislike.

From the very beginning, "That's not what the teacher said, bro, you're wrong..."

Later, "The teacher must have made a mistake again! The teacher is too much! Rubbish!"

In the end, "I don't want to remember the teacher's anymore! It's useless at all! Hey! It's useless! Throw it away! Throw it all away!"

Xu Heng rolled his eyes, "Some misleading is useless! Some, you still need to use it if you want to make a correct judgment."

Zhou Xiaoya, "But, bro! Everything you told me was denying the teacher! Now you're telling me to agree with them?"

Xu Heng, "Uh..."

It's another one or two hours of lectures and questions.

From mathematics to physics, from physics to geography, from geography to...

Until ten o'clock at night.

Xu Heng had just rested when his cell phone rang.

"Ring Ling Ling..."

It was Yue Pingting calling.

Xu Heng, "Hello?"

Yue Pingting, "Hello...Xu Heng, you're not at school?"

Xu Heng, "Well, I'm home, and now I'm at my uncle's house."

Yue Pingting, "Oh oh oh, I have a question to ask you..."

Xu Heng, "???"

"How do you feel about this test?"

Yue Pingting, "It's not bad, it's just..."

The two chatted for a long time, then Zhou Xiaoya ran out, and in the living room, both Zhou Luzhe and Geng Xiaoyan were there.

Zhou Xiaoya ran up to them mysteriously.

"My brother was on the phone with a girl at night."

Zhou Luzhe, "!!!"

Ge Xiaoyan, "!!!"

"Your brother... is in love?"

Zhou Xiaoya, "I think it's probably true! Otherwise, why would people call my brother at night!"

brush!

In an instant, Zhou Luzhe called Zhou Xiu'e.

"Sister! Xu Heng! Is Xu Heng falling in love?"

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·??????????????

Zhou Xiu'e was speechless, "I almost fell asleep! What's the matter with you kid? You were taken aback! Xu Heng fell in love as soon as he fell in love! What's all the fuss about!"

Zhou Luzhe, "Doesn't this affect your studies?"

Zhou Xiu'e rolled her eyes, "Ask yourself! Ask yourself! Let me ask you, when you said this, were you guilty?"

Zhou Luzhe, "I...!"

Ok!

He regretted it after he finished speaking.

"But... it affects your studies! Sister! Don't you care?"

Zhou Xiu'e, "Don't worry about it! I know you are kind, but Xu Heng's grades will not be affected!"

"Besides...the little Yuezi is already living in our house, and where is the daughter-in-law whom your brother-in-law and I agree with!"

Zhou Luzhe, "!!!"

"..."

In the living room, the three views of Zhou Luzhe's family were overturned.

Inside the study.