"Advanced Algebra...... Got it! ”

Xiao Ran stood beside the mathematical classification bookshelf, his eyes swept over the rows of books, and soon found the white leather book with advanced algebra written on it.

In his previous life, he was tormented by this book.

After four years of college, the only thing he remembered was the law of Lopida.

This is also thanks to his second roommate in his previous life, when he checked the results in the dormitory, after seeing that he had a high score of 60 points and a low score, because he reviewed the law of Lobida all night before the exam, he instantly became a faithful believer in the law of Lopida at this moment.

Immediately triumphantly swore and cheered in front of them: "Wuhu! The law of Lobida is the first in the world!! ”

"Don't tell me anything about the Taylor formula, the Mark Laulin formula, what is the entrapment criterion? Is there a Lobida formula that works? ”

"The limit is not difficult, Luo is finished!"

"Luo to the limit does not exist, but also Luo, all the way to the ancestral tomb of the function!"

This remark impressed him deeply, and until he graduated, he had almost forgotten the knowledge of high mathematics, but the five words of the law of Lobida remained in his mind.

The memories of the past drifted away with the wind, Xiao Ran was stunned, then picked up advanced mathematics, found a quiet corner of the library, opened the book, and then put on headphones.

Take out your mobile phone and log in to station B, there are many university high math teaching courses on station B.

With the teaching of these courses, Xiao Ran's mind was quickly immersed in the textbook.

Little by little, time passed.

Soon the content of the first two chapters of Advanced Algebra, the solution of linear equations and the content of determinants have been almost pre-cooked.

Just as he was about to move on to the next chapter of the review.

A shy voice rang in his ears.

"Classmate, are you reviewing advanced algebra?"

Xiao Ran raised his head and saw a beautiful girl with a double ponytail looking at him embarrassedly.

"Is there something wrong?" Xiao Ran nodded, politely took off the headphones and asked.

"That....... Can I ask you a question? The girl pointed to the book of advanced algebra on his desk, then folded her hands and whispered: "It's the advanced algebra you reviewed, and there is a question that I am not very good at ......."

The girl was a little red after speaking.

Xiao Ran was a little silent when he heard this.

When did you get the illusion that I would too?

He had just finished the first two chapters, and he might not have as much knowledge as this girl.

To be honest, he felt that this girl had found the wrong person.

Xiao Ran wanted to refuse, he thought about it, so he asked, "Do you have a boyfriend?" ”

The girl was even more shy, she raised her head and glanced at Xiao Ran secretly, lowered her head again, and twisted and pinched for a long time before whispering: "Not yet." ”

"Then I won't!"

Girl: "...... Yes??? ”

One sentence instantly burned the CPU of the girl's brain.

She didn't understand Xiao Ran's logic for a long time, I don't have a boyfriend, shouldn't you be happy, right, by the way, invite me to sit down, explain the topic to me, and add a WeChat by the way after speaking.

Of course, if you invite me to dinner at noon, it is not impossible if we can talk.

But you won't mean a few?

"So what if I say I have a boyfriend?" The girl asked subconsciously.

Yes? Not so much!

Yes or no, that's a philosophical question.

Xiao Ran was silent for a moment, "If you have a boyfriend, shouldn't you ask your boyfriend, why do you ask me?" ”

Double Ponytail Girls: ......

You just don't tell me about it!

Xiao Ran ignored the girl anymore, put on the headphones and immersed herself in the ocean of learning again.

The matter of the double ponytail girl was just a small episode for him, and he quickly entered the state without distractions.

Chapter 3, Section 1, Section 2......

Before you know it, the morning has passed.

At half past twelve o'clock in the afternoon, Xiao Ran was woken up by the hunger in his stomach.

He was going to borrow this book of advanced mathematics and continue to read it.

Only then did he notice that the girl who had asked him a question just now had not left.

Instead, he sat across from her, gnawing on a pen and tangled in a math problem.

What is the problem that can bother this girl all morning?

Xiao Ran couldn't help but be a little curious, walked up to her, tilted his head and glanced at the math problem that had plagued her all morning.

It's a question of diagonalization.

Let A be an nth-order compound matrix, and prove that A satisfies A^k=In, and that A is diagonalized and that the eigenvalues are all k-order unit roots.

The girl with two ponytails didn't notice that there was an extra Xiao Ran beside her.

At this time, she was biting the tip of her pen with a tangled face, and she didn't know what to do with the problem in front of her.

At that moment, a gentle, magnetic voice sounded in her ear.

"You can consider using minimal polynomials to solve this problem of diagonalization."

The double ponytail girl paused for a moment, and then nodded suddenly: "Yes!" ”

"Thank you..... Huh? She raised her head and was about to thank her, but found that it was Xiao Ran, "It's you?" ”

Xiao Ran raised his eyebrows and asked, "Is it unexpected?" ”

"No, no, but ..... But aren't you unwilling to teach me? The girl's face turned red instantly, and she quickly explained embarrassedly.

Xiao Ran showed a noncommittal expression, "Idle is idle." ”

As he spoke, he then asked, "You understand?" ”

Schoolgirl:......

"I still don't understand."

So what does it mean for you to show a sudden realization?

Xiao Ran glanced at the girl speechlessly, and then said, "Give me the pen!" ”

The girl hurriedly handed over the pen, and thoughtfully let go of the seat for Xiao Ran to sit down.

Xiao Ran was not polite, took the pen and sat down, "If you want to prove this problem, you must first know that the sufficient and necessary condition for the non-heavy root of the minimal polynomial of the compound matrix A is that A can be similarly diagonalized. ”

"With that in mind, it's much easier to make this question."

Xiao Ran explained while doing it.

"If A^k=In, then f(x)=x^k-1 is a zero-zero polynomial of A, and f'(x)=kx^(k-1) and f(x) have no common factor greater than 0, so f(x) has no double root. Since f(x) is divisible by the minimal polynomial, the minimal polynomial has no heavy roots, so that A is diagonalized. Let λ be the eigenvalue of A, then there is a non-zero vector ξ such that Aξ=λξ, ξ=A^kξ=λ^k, thus λk=1 ......"

It's amazing!

The girl watched in a daze as Xiao Ran finished solving the problem that had plagued her all morning at a flowing speed.

Is this guy still human!

A scumbag looked up to the mood of the school bully.

"That's it." Xiao Ran finished proving this question, threw the pen, and looked up at the girl: "Understood?" ”

The girl's face turned red instantly, and she whispered, "Understood!" ”

Xiao Ran didn't care whether she really understood or fakely understood, just assumed that she understood.

"Okay, then I'll go first."

As he spoke, he got up and prepared to leave.

"Wait, classmate!" The girl looked at Xiao Ran with some embarrassment, "That...... May I ask you a question, why do you still wear sunglasses in the library, don't you feel awkward......"

To be honest, she has been holding back this point for a long time, but she has never had a chance to ask.

It wasn't until Xiao Ran was about to leave that she couldn't help but ask.

"That's what you say?" Xiao Ran took off his sunglasses casually, "I'm sorry, I'm used to it." ”

Looking at that familiar face, the girl gradually opened her mouth wide, and her face was sluggish.

Who am I? Where am I? What am I doing?

The girl can't help but doubt her life at this moment!

This is the big star Xiao ...... Xiao Ran??!!

"It's nothing, I'll go first!"

Xiao Ran waved his hand and walked towards the door of the library, leaving only the girl with a messy face.