Chapter 366: Pen!

Chapter 366
The two fierce quarrel sounded.
The quarrel was loud and attracted the attention of some people nearby, including Cheng Nuo and He Youjun.
Two people, black and white, stood directly on the stone steps of the activity center, arguing with red faces and ears.
Depending on the posture, if no one stops it, I'm afraid it will be a fight soon.
Cheng Nuo sat aside, looking sideways at this side, completely watching a play.
Cheng Nuo is not clear about the reason for the two quarrel, but from the words they talked, it should be about the solution of a certain mathematical problem, which produced an irreconcilable difference.
Gradually, the two people who couldn't tell the victory or defeat began to push each other.
The other two companions with them, the old gods were there, and they didn't seem to persuade them at all.
Depending on the situation, it is already commonplace.
Suddenly, a white classmate was pushed by classmate Xiaohei, his body's center of gravity was unstable, and he dumped directly to one side.
And sitting on that side were Cheng Nuo and He Youjun.
Fortunately, Cheng Nuo was a man who was able to win with speed. He reacted very quickly, supporting the fallen white classmate with both hands.
The white classmate fell into Cheng Nuo's arms, leaning on Cheng Nuo's generous chest, and something strange seemed to flash across his azure eyes.
The white classmate looked at Cheng Nuo Dongfang's sharp cheeks and swallowed subconsciously.
Inexplicably cold behind Cheng Nuo, he had a bold conjecture.
But in order to maintain his image, Cheng Nuo politely helped the white classmate up.
The white classmate shook hands with Cheng Nuo excitedly, "Hello, my name is Chali, thank you very much for your righteous action!"
Cheng Nuo smiled friendly, "Cheng Nuo, from China!"
The white classmate was even more excited, and put his arm around Cheng Nuo's shoulders, "Hua Guo? I have been there! Cheng, I have to say, that is a very interesting place!"
"By the way, Cheng, which college do you belong to?" Classmate Chali was curious.
Cheng Nuo thought for a few seconds, "Uh..., it should be regarded as a student of mathematics in the Faculty of Science!"
"What! You are also majoring in mathematics! Great!" Classmate Chali, who was always excited, was excited again.
Regardless of whether Cheng Nuotong agreed, he took Cheng Nuo by the arm and walked to the little black classmate.
With his strong body, Xiaohei succeeded in defeating Classmate Chali by force, but he would not be easily convinced.
"Hey, Luke, I found a classmate who majored in mathematics. How about letting him judge our opinion for us?" Chali said to classmate Xiaohei.
Student Xiao Hei hugged his arms and glanced at Cheng Nuo lightly, "Chali, are you kidding me! What we are discussing is not an examination question, but an advanced math problem."
"As for your undergraduate friend, I'm afraid it's hard to understand what we discussed!"
Chari didn't care about Xiao Hei's sarcasm.
Cheng Nuo couldn't help it.
Eat your rice at a young age! ! Have you never seen a talented person?
Lao Tzu is looked down upon by all kinds of people at home, but it is still the same when he goes abroad!
This force, if you don't finish pretending, and pretend to be pretty, I'm simply sorry to call it the king.
Cheng Nuo stretched out his hand, his tone was light, and he spoke to Chali, "Bring the question?"
Chali didn’t react to the sudden change in the tone of the Chinese friend he just met. After a few seconds, he handed a piece of paper to Cheng Nuo from his schoolbag and said,
This is where we are. I found a problem when I visited ResearhGate, and there is no correct way to solve the problem."
ResearhGate, Cheng Nuo has heard of this website. Simply put, it is a Favebook for scientific researchers.
Cheng Nuo took the title and read it again.
[Prove: When 2≤n≤N, the following continuous product inequality always holds:
√2√3√4√5……√n≤3/2^n-1√n+2≤√1+2√1+3√1+4√1+……+(n-1)√1 +n】
Cheng Nuo wanted to finally know why he heard the words Ramanujan's identity in the quarrel between the two before.
It turns out that this problem is a modification of Ramanujan's identity.
The so-called Ramanujan identity refers to an identity named by the great mathematician Ramanujan.
The formula is: 3=√1+2√1+3√1+4√1+5√1+n……
There are two more mainstream methods to prove the identity, so I won’t repeat them here.
In short, the topic that Chari showed to Cheng Nuo is closely related to Ramanujan's identity.
Classmate Chali then handed Cheng Nuo another piece of paper with dense mathematical formulas written on it, "Hey, this is the proof step of Luke. He thinks his proof step is correct and there is no problem. But I think he The proving process of "is wrong! Because of this, we quarreled!"
It turned out to be for this reason!
People who study academics, even the reasons for quarrels, are of such a high-end atmosphere.
"Then you think his step was wrong?" Cheng Nuo asked.
Chari scratched his head, "I don't know, just by feeling."
Cheng Nuo: "..."
Brother, you cheated!
Cheng Nuo was speechless for a few seconds, then took the A4 paper full of steps and scanned it line by line.
There are not many formulas, just one page. In three minutes, Cheng Nuo finished watching.
After reading it, Cheng Nuo looked up and met the gaze in Chali.
"How?" Chali asked, seeming to have great expectations for this Chinese student who had never met before.
Cheng Nuo smiled slightly and stretched out his hand, "Pen!"
"Here, here, and here, the steps are all wrong!" Cheng Nuo took a pen and clicked on four or five places and explained the reason for the error in detail.
This question should be regarded as a difficult level for most doctoral students.
And depending on the age, Chali and the Xiaohei classmate should still be studying for a master's degree, even if they are MIT students, it does not mean that they can easily cross-level combat.
Such difficult topics still embarrass them a bit.
The Xiaohei classmate who was pointed out by Cheng Nuo was ashamed, but he still insisted.
His face flushed, and his fingers pointed at Cheng Nuo with trembling fingers, "Aren't you very strong? Give me the pen, you can write!"
Cheng Nuo smiled and shrugged, smiling slightly. "no problem!"
What I am waiting for is your words, classmate Xiao Hei!
The first pretend tour of a foreign country~EbookFREE.me~ I didn't expect the first stop will happen here.
The sky is destined, so let it be.
Holding the pen, Cheng Nuo started to move.
On the left side of the proband, [when 3≤k≤N, Bernoulli's inequality can be obtained: 2(3/2)^k-2=2(1+1/2)^k-2＞2 (1+k-2/2)=k. That is kamp;amp;lt;2(3/2)^k-2, k=3,4,……n, so, √2√3√4√ 5√……√n≤√2√2(3/2)√2(3/2)^2√2(3/2)^3……】
Prove again on the right side, [because k=√1+(k-1)(k+1), k=3, 4, 5,..., so 3=√1+24√1+2√1 +35=√1+2√1+3√1+46=……=√1+2√1+3√1+4√1+……+(n-1)√1-n (n-2)……】
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PS: Did you start school soon?