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

"Take each other's questions! Answer each other's questions!"

0 0 ...

"So, do you have any objections?"

Everyone looked at each other, unconsciously, their eyes fell on Dong Fangyuan and Wang Mengyao.

"Dong classmate! Wang classmate! You have done enough questions! We trust you, you go and give it!"

The group leader, Feng Hechuan, Luo Jianing and others looked at Xu Heng expectantly, "Big Brother Xu Heng! Come on!"

Xu Heng left his seat and walked towards the blackboard.

Before everyone could respond, he walked to the blackboard and wrote down:

Find all polynomials in two variables that satisfy the following conditions:

(1) P is homogeneous of degree n.That is, for all real numbers t, x, y, there is P(tx, ty)=tn·P(x, y)

(2) For all real numbers a, b, c, P(a+b, c)+P(b+c, a)+P(c+a, b)=0

(3) P(1)=0.

After finishing writing, he didn't leave, just stood where he was.

This matter has started today, if it is not resolved, they will definitely trouble themselves again in the future.

Instead of this, let's solve it in one go!

Finally, under the invitation of everyone, Dong Fangyuan and Wang Mengyao stepped onto the podium and wrote their own topics respectively.

Before Zhu Tiesen had time to ask the three students to choose topics from each other, Xu Heng had already walked over.

Zhu Tiesen, "???"

Dong Fangyuan, "???"

Wang Mengyao, "???"

Students, "???"

topic:

已知：0.301029＜lg2＜0.301030，0.477120＜lg3＜0.477121，求**的首位数字。

Xu Heng basically didn't think about it.

He immediately raised his arm and began to write under the question.

解：因为lg2000（1979次方）=1979（3+lg2）=5937+1979lg2

<1979lg2<595.738370

And lg5=1-lg2<0.70

lg6=lg2+lg3＞0.77

所以6532+lg5＜lg2000（1979次方）＜6532+lg6

即5×10（6532次方)＜2000（1979次方）＜6×10（6532次方）

So the first digit of 2000 (to the power of 1979) is 5.

After finishing writing, Xu Heng didn't even look at it, and turned to look at another question they asked...

Zhu Tiesen, "!!!"

"Wait, student Xu Heng... What I said is, the three of you will cross-exchange the questions and answer them. It's not you doing two questions alone!"

Right now!

Xu Heng deliberately pretended not to hear.

And all the students here feel like they are dreaming!

They once suspected that they were hypnotized, and they felt that what they saw was not reality!

"Impossible! How is this possible...!"

PS: Why is the data motionless!Is it stand-alone?

The little author is so miserable!Give some support!Thank you everyone!It is really not easy to stick to the code words of more than 2 characters every day, and my hands are freezing to death!

Ask for all support!Good luck to those who support you!I wish you peach blossom MAX wow!

Ask for automatic subscription!Ask for flowers!Ask for an evaluation ticket!Ask for a monthly pass!Ask for a reward!Four.

Chapter 197

"This……!"

Feng Hechuan finally couldn't help it at this time, "This time, no one will say that they are also in collusion with Xu Heng, and they are tricky?"

Luo Jianing also echoed with a smile, "Some people just sit and watch the sky! I don't know there are people outside!"

She has always been used to make up the knife, or have a poisonous tongue!

Many students were speechless.

They stared at the blackboard and began to doubt life.

The one with the greatest impact was Wang Mengyao.

This question was posed by Wang Mengyao!

When she first encountered this question, she had no idea what to do, but she never expected that Xu Heng would answer it directly before the blackboard was warmed up.

She frowned and froze in place.

"hiss……!"

Taking a deep breath, she clenched her fists and kept her body in place.

Dong Fangyuan came over to comfort him, "Is this question often seen? So it was..."

Wang Mengyao looked at Dong Fangyuan and asked, "Do you often see this question? Anyway, I only encountered it once in various question banks! Please don't deceive yourself!"

Dong Fangyuan, "%￥#@##￥..."

Wang Mengyao, "It depends on your question!"

Although Zhu Tiesen meant that no one chose to answer a question that was not his own, but Xu Heng had already stood in front of Dong Fangyuan's question.

And Wang Mengyao, Dong Fangyuan, and other students in the class stared at Xu Heng, wanting to see how he answered Dong Fangyuan's question.

"The first one may have been done by him by chance, so it's understandable!"

"The second question, he is not so lucky!"

"..."

Dong Fangyuan's question:

The subset S of the rational number set Q has the following properties: (1) If a∈S, b∈S, then a+b, ab∈S;

For every rational number r, r∈S, r=0 has one and only one.

Prove that: S is composed of all positive rational numbers.

Xu Heng is basically a seamless connection.

After reading the questions, he slowly raised his arms again and began to answer questions on the blackboard.

The students panicked!

Finally someone can't stand it anymore!

"I'm sure! He can do this question too!"

"???"

"What the hell?!"

"Two questions! If the first question is encountered by chance, then the second question...!"

Swish swish!

The students looked at Dong Fangyuan.

Everyone looked at Dong Fangyuan!

Dong Fangyuan was stunned, he was stunned, his eyes widened, and he stared at the problem-solving ideas written on Xu Heng's blackboard.

"Damn! Dong Fangyuan is completely confused!"

"Xu Heng's doing these two questions is the same as doing one plus one equals two!"

"Fuck! This is simply not human!"

"They are Dong Fangyuan and Wang Mengyao! One is No.1 in the Mathematical Olympiad competition! The other is No.2! They were recommended in the first year of high school! They have been interested in mathematics since they were young. In fact, the questions they asked have some considerations!"

"The possibility of being met by Xu Heng is really too small!"

"Could it be that Xu Heng has already solved all the questions they have solved?"

"So that's why Xu Heng is so leisurely every day?"

"Don't forget...he's from the test group!"

Everyone started to look at Xu Heng squarely!

Just when everyone's views on Xu Heng changed, suddenly!

Xu Heng stopped, then turned around, picked up the blackboard eraser, and erased the entire problem-solving process he had written.

Everyone, "!!!"

The corners of many students' eyes twitched, "What's going on, I can't answer it?"

Wang Mengyao and Dong Fangyuan frowned even more.

Wang Mengyao, "According to his way of thinking, it should be right. Dong Fangyuan, isn't your way of thinking when you do this question?"

Dong Fangyuan clenched his teeth and clenched his teeth, "When I found this question, there was no answer... I couldn't do it when I was halfway done!"

"So this question, I have always kept it in my heart. I planned to ask the professors this time! I have never had time..."

"But Xu Heng seems to be writing today, or mine is a few more steps..."

Wang Mengyao, "!!!"

She was a little surprised, she never expected that Dong Fangyuan would bring up a topic that she was not sure about.

"Presenting a question is different from doing it! Student Dong!"

Dong Fangyuan also had some regrets.

He fixed his eyes on Xu Heng...

Wang Mengyao, "Why don't you just tell him the truth!"

When Dong Fangyuan was considering whether to stand up and tell the truth...

Xu Heng suddenly took a step back and looked at the whole question again.

classmates,"???"

Someone let out a long sigh of relief, "Phew... slap your face swollen to pretend to be fat! It should be impossible!"

"Hehe! If Xu Heng can answer this question so quickly! No! Give him 15 minutes! No! Give him 10 minutes! If he can answer this question, I will really be convinced!"

"It's finally revealed!"

"Look! This is what happens when you overestimate yourself..."

people!

They all like to make things worse.

Zhu Tiesen had absolute confidence in Xu Heng, and he also discovered the problem with this question.

Looking at Dong Fangyuan's tangled expression, Zhu Tiesen will probably be able to make a fuss.

Just about to speak...