pertwk Chapter 29 Borrowing books right on time
Chapter 29 Borrowing books right on time
Lu Feng, who had just finished evening self-study and was having dinner, walked on the asphalt road on campus, his shadow stretched long by the streetlights.
At Hong Kong City University in 2012, there were still many students jogging on the playground before 9 p.m.
He reached out and pinched the back of his neck, and his cervical spine made a few crisp "crack" sounds.
This tangy flavor is absolutely amazing.
The afternoons are full of classes, and Hong Kong City University also requires first-year students to attend an hour and a half of evening self-study sessions.
He took his phone out of his pocket and skillfully plugged the wired headphone plug into the headphone jack.
The screen lights up; open the media player.
"My mind is starting to wander, you're making me hallucinate, I want to be with you, I don't want to experience separation again..."
Lu Feng hummed along to the rhythm for a couple of lines, his tense nerves relaxing slightly.
I glanced at my watch; it was 8:25.
The borrowing system on the second floor of the library closes promptly at 8:30.
Lu Feng quickened his pace, taking three steps at a time to climb the stairs, pushing open the glass door of the second-floor reading room, and quickly went to the bookshelves to find books. The librarians were quite good at arranging the books; basically, all the relevant books were lined up and easy to find.
The reading room was almost empty, and the cleaning lady was mopping the floor.
Behind the management desk at the entrance, Lin Wan was stuffing several postgraduate entrance exam materials into her canvas bag, her hand already reaching for the power button on the computer tower.
"Wait a minute." Lu Feng slammed three thick hardcover books onto the table.
Lin Wan paused, then looked up.
Upon seeing who it was, she pushed up her black-rimmed glasses and gave a helpless smile: "Junior, you really don't want me to leave work on time, do you? The system will automatically lock in two minutes."
"Sorry, I just finished evening self-study and ran over here." Lu Feng took a breath and pointed to the books on the table. "Could you please help my sister?"
Lin Wan didn't say anything more, sat down again, and picked up the book to look at the code next to it.
Classical Electrodynamics.
Introduction to Plasma Physics
"Fundamentals and Applications of Superconductivity".
Lin Wan raised an eyebrow slightly as she looked at the book title that popped up on the computer screen.
She deftly typed on the keyboard, completed the borrowing registration, and returned the book to Lu Feng.
"Alright, remember the 30-day deadline."
"Thank you." Lu Feng stuffed the book into his bag and turned to walk towards the stairwell.
Lin Wan watched his retreating figure, quickly stuffed her documents into her bag, zipped it up, and jogged after him.
"Junior Lu Feng, wait a minute."
Lu Feng stopped at the corner of the stairs and turned around.
Lin Wan, carrying her bag, walked a few steps to him and her gaze fell on his bulging backpack.
"I remember you studied mechanical engineering, right? Why are you suddenly borrowing so many books on electrical engineering? And they're all graduate-level theoretical books."
A first-year mechanical engineering student, whose course schedule hasn't even included university physics yet, is jumping straight into electrodynamics and plasma physics—a leap bigger than doing the splits.
They're not afraid of getting hurt.
"I'm quite interested in this," Lu Feng said calmly.
"I might use it in some future research."
interested?
Lin Wan's lips twitched.
Who would consider plasma physics a hobby? It's full of partial differential equations that can make you sick of reading them.
Indeed, the interests and hobbies of geniuses cannot be deduced using common sense.
The two walked down the stairs side by side and exited the library.
As the cool autumn breeze blew by, Lin Wan tidied her hair, which had been ruffled by the wind.
"Actually, I saw your math formulas when I passed by the library before," Lin Wan said, her tone somewhat tentative.
Lu Feng turned to look at her, but didn't reply.
"Just last month, you sat by the window, deriving mathematical formulas all afternoon." Lin Wan smiled. "I saw the draft paper you left on the table; those derivations... were amazing. Even Professor Ye from the mathematics department came to see you."
Lu Feng paused.
Question marks all over his face.
Why is this senior student staring at me for no reason? And even peeking at my draft paper? What is this, academic stalking?
However, what Lu Feng didn't know was that Lin Wan had provided a significant amount of emotional value to enable him to summon Newton in such a short time.
"I just figured it out by trial and error, and I got lucky and managed to get it working," Lu Feng casually replied.
"Don't be modest," Lin Wan sighed. "I studied accounting, and my math foundation is so-so, but when I passed by and saw you writing those complex functions and integral transforms, it seemed like it was no problem for you at all. It made me question my own existence."
She stopped, took out her phone, and opened the QQ QR code interface.
"Hey junior, let's add each other on QQ. I've been having really trouble with matrix problems lately, I just can't seem to find the right approach. You're so good at math, can I ask you for help if I have any questions in the future?"
Lu Feng took out his phone to scan the QR code.
With a "beep", the friend request was sent.
"Okay." Lu Feng put his phone back in his pocket. "Matrix problems are nothing more than transformations of eigenvalues and eigenvectors. Which part are you stuck on?"
As Lin Wan accepted the friend request, she frowned and recalled, "It's the kind of matrix equation problem with parameters, and the quadratic to standard form problem. I always get confused halfway through the calculation, and I always make mistakes in the orthogonal transformation steps."
After listening, Lu Feng pondered for a moment.
"This is from Chapter 5 of Linear Algebra. Are you a sophomore? It's easy to get confused when you first encounter this part. Actually, you just need to remember that a real symmetric matrix can always be orthogonally diagonalized. Just normalize the eigenvectors and then combine them into an orthogonal matrix."
The air suddenly became quiet.
Under the streetlights, Lin Wan's face was visibly red, all the way to her ears.
She bit her lip, her voice barely audible, "I...I'm a senior in college, and I have to take the postgraduate entrance exam in two months."
Lu Feng: "..."
Good guy.
For senior students preparing for postgraduate entrance exams, with only two months left before the exam, is it still possible to get stuck on quadratic and standard forms?
This level of achievement, while not necessarily needing improvement, has essentially meant a farewell to 985 and 211 universities.
Lu Feng was internally ranting, but on the surface he remained calm and composed.
He cleared his throat, trying to ease the awkwardness: "Senior year...time is indeed quite tight then. Linear algebra is all about understanding the essence. Don't memorize the steps; think about its geometric meaning. A matrix is essentially a linear transformation. Quadratic to standard form means finding a suitable coordinate system to make the transformation look as simple as possible."
Lin Wan stared at him blankly.
These are words that teachers in postgraduate entrance exam preparation classes have also said, but when spoken by a freshman, coupled with his calm and composed expression, they have a strange persuasive power.
"Geometric meaning..." Lin Wan muttered thoughtfully.
"Yes." Lu Feng nodded. "Go back and review the section on basis transformation and coordinate transformation in your textbook. Don't do any problems, just focus on the concepts. Once you understand them, quadratic form problems will be a breeze."
"Okay, I'll check it when I get back!" Lin Wan's eyes lit up, as if she had grasped a lifeline.