love you like a song

The sun is very harsh.As soon as he walked out of the house, Mu Zi'an saw from a distance the man in black who brought her in just now, standing at the door waiting for him, saw Mu Zi'an running over, and asked.

"Are you going to the Aerospace Research Institute next?"

"Yeah." Mu Zi'an nodded, "Just now that person said—" If I don't go, it will be very troublesome.

However, before she could finish her sentence, the man in black stretched out his hand and interrupted her: "Don't tell me, there are some things I can't know."

"Oh——" Mu Zi'an nodded, and asked cautiously, "Then may I know your code name?"

"No."

"..."

It's funny to think about it, code name, organization, etc., aren't they things that are only mentioned when children play house, where will I take myself next?Base?

This was not what Mu Zi'an had expected - he thought that attending a lecture would be noticed by so-called aerospace experts if it was good, and would make him famous, but if it was not good, it would be regarded as an experiment.

I thought I would be able to go home at ten o'clock, and then have lunch with Gu Nan, but now it seems that I can't.

Now that mobile phones have not become popular yet, Gu Nan has a pink Nokia. He wanted to buy another one for Mu Zi'an, but Mu Zi'an's previous school did not allow him to wear mobile phones, so this matter did not succeed. It doesn't even work to call Gu Nan.

I can't help but think of last night, Gu Nan didn't know where to go alone, drank so much wine, just thinking about it made me feel annoyed, so I deliberately didn't want to think about Gu Nan, let her worry about it alone, hum!

It was the first time in Mu Zi'an's life that he liked someone, but it ended in failure. It was such a failure that Mu Zi'an didn't even dare to think about it anymore.

——It was really embarrassing. After confessing, the man tried every means to avoid himself, as if treating himself as a virus carrier.

However, Mu Zi'an could no longer face Gu Nan normally.

She was very uneasy and uneasy, as if she was suspended in mid-air by something. Gu Nan agreed to disagree, the decision was all in her hands, and Mu Zi'an had no right to interfere.

Strolling on the street, occasionally looking up at the sky, half an hour passed quickly, and it was already eleven o'clock in the morning.

When Mu Zi'an walked to the research institute, he was surprised to find that the guard was still looking at him fiercely. "Hey, what are you doing here again?"

"...301B174."

"what?"

"303F098"

"Code name, both."

"..." The guard looked at Mu Zi'an very seriously, making her feel uncomfortable, and the staring eyes were suspicious and disbelieving.

Fortunately, the guard didn't say much, and waved to Mu Zi'an. "Come in, come with me."

"..."

The guard said lightly. "You must remember that what you said just now is not the code name of the organization, but your code name. Don't say it easily, otherwise people will think you are an idiot."

The man's expression was completely different from the beginning, the original fierceness was covered up indifferently, as if he was acting just now.

Mu Zi'an nodded. "Then what should I call the organization?"

"Don't mention the organization casually." The guard said lightly, "No one can find out that you have joined this organization. If someone asks you, you can't tell your code name, you can only say 'I don't know'."

"..." Well, it's still quite mysterious.

Mu Zi'an actually didn't take it seriously at all.

What kind of organization is this?The Ministry of National Security or the Ministry of Military Affairs?Of course it's impossible. To put it mildly, it belongs to the head of the government, but in fact it can't be the kind of large department she thought, otherwise how could it find a child like herself.

Thinking about this point clearly, Mu Zi'an didn't care too much about it, his face was depressed, although winter was approaching, and the sun at noon was very dazzling, at this time, he should have taken a nap.

After walking through a short section of the corridor, the guard took a magnetic card from his chest, swiped it, and took a fingerprint and iris photo before the door opened automatically.

As soon as he entered, he could only feel the shady air rushing towards his face. There were five elevators and a stairway on both sides. The guard led Mu Zi'an to the stairway and said.

"You have to go to the second basement floor by yourself. From here, you can enter the first room on the left. You have to knock five times on the door, and then say one of your code names, and that's it."

"..." is another code name.Mu Zi'an really didn't like this.

Nodding his head, he went down the stairs.

This staircase is a spiral circular staircase, surrounded by many rooms, I don't know which one is the 'first one on the left', but soon, this staircase ended, and then I saw a wall in front of me.

Mu Zi'an looked to the left and then to the right, and there really was a way to go, the room embedded next to it.

She knocked on the door five times, coughed, and said. "303F098."

Sure enough, a rather old voice came from the door.

"The button in the lower left corner of the door, press it, and turn right."

Mu Zi'an did as he did, and the door really opened.

Although it is the second basement floor, there is no gloomy feeling here. The lamp above the head is very bright. Looking forward, a pale-haired old man is sitting in front of a mahogany table, looking down and writing something.

Mu Zi'an closed the door silently, opened his mouth and didn't say anything, when the old man looked up at him, showing a very puzzled expression, and asked her. "how old are you?"

"14 is old."

"Junior high school student?"

"College Students."

The old man pushed the glasses on the bridge of his nose, looked Mu Zi'an up and down again, and then pointed his finger at the stool in front of Mu Zi'an. "You sit down."

After Mu Zi'an sat down, the old man took out a piece of paper in front of him and handed her a pen. "Please solve this problem, so that we can explain it later."

Mu Zi'an looked down, it was a math problem.

It's not a problem.

This is a problem of finding the exact solution of three fifth-order nonlinear equations. There are many ways to do it. You can use Newton's iterative method or other iterative methods, but it is really simple.

Mu Zian used Newton's iterative method to find out within a minute, and handed it to the old man hesitantly.

"--Is this okay?"

The old man looked around. "Try again with other methods, and see if you can calculate the convergence and error estimation formula of the iterative method between them."

ah?How is that possible.

Mu Zi'an immediately asked back: "How do you count? I didn't..."

"If I knew how to calculate, why would I need you?" The old man said without raising his head, choking Mu Zi'an.

Mu Zi'an glanced at the question, if he wanted to get the exact errors of the three fifth-order nonlinear equations...

Then she had to assume a traveling wave solution first, then convert the three fifth-order nonlinear equations into ordinary differential equations, and solve them with the aid of the auxiliary equation method and Mathematica software, in order to finally obtain a series of accurate values.

But she doesn't have Mathematica software now.

Mu Zi'an thought for a while, and suddenly thought of something.

Linear partial differential equations have important applications in real life and in the fields of biology and physics, so if you relate to other aspects...

Mu Zi'an thought carefully about the arithmetic method that can find infinitely precise values, and almost reflexively remembered the method of dichotomy.

Can the dichotomy be found?Of course, it is possible to use the value calculated just now as a logarithmic function to find the zero point. Although it is troublesome, there is no need to use software.

Two years ago, Gu Nan practiced her computing power fiercely, and it's not like she didn't come up with such a problem.

Mu Zi'an looked up at her watch. It had only been 10 minutes. She pondered for a while and handed the draft paper to the old man... The paper was accurate to eight digits after the decimal point.

So fast, maybe Lily's memory helped Mu Zi'an to some extent.

The old man picked up Mu Zi'an's calculation paper and looked at it carefully. He squinted his eyes and didn't react in surprise. After a while, he stood up unsteadily, took out a lighter from the side drawer, and put the The paper burned.

Mu Zi'an secretly felt strange, could it be that she made a mistake?Then there is no need to be so angry, burn all the paper, as for?

The old man cleared his throat.

"Welcome here, 303F098."

The author has something to say:

Wolf... the next chapter will be about Rowling and Lily