Chapter 4 Is there anyone who can't do it?
Happy times are always short. \b
Li Mu realized the meaning of this sentence for the first time in the process of learning.
From reading at 6:40 in the morning until the opening of the library at 8 o'clock, he didn't seem to come back to his senses, and after entering the library, time passed like running water.
Library-canteen-library-canteen-library-dormitory.
That's it for a day's itinerary.
In Li Mu's perception, it seems that he has never passed such a fast day in his life.
"Old Li, you are a real bully."
Back in the dormitory, Zhang Lei and the others surrounded Li Mu.
"How did you manage to read the book for a whole day?"
"Share you know the trick?"
The three of them saw with their own eyes that Li Mu never put down the book at all.
On the other hand, they didn't come to the library in the afternoon, and they returned to the library after dinner. Although they counted as eight or nine hours in the library, in fact, There are also two or three hours of time spent in a daze or playing with mobile phones.
When he heard their questions, Li Mu touched his nose and said, "Just look at it that way, there's no trick to it."
"Can you read books like calculus?"
"Uh..." Li Mu asked suspiciously: "Don't you guys think reading is a very happy thing?"
Zhang Lei, Xu Sheng, Chen Kaiming: "..."
"You have changed, dog."
The three shook their heads and scattered back to their seats.
They have no common language with Gouzi.
Li Mu smiled calmly.
Gouzi has not changed, but his mind has changed.
...
Nothing to say all night.
The next day arrived as promised.
Of course, as promised, there is also a small multivariate calculus exam.
Before the third class in the morning, more than 30 students from Class 1 of the Physics Department had already sat in the classroom, one person at a table.
"As I said last week, there will be a small test in this week's course to test how well you have learned during this time. This is also our practice, and it was the same when we taught you one-dimensional calculus last semester."
"The grades are included in the usual grades. We have three small exams this semester, including a midterm exam. The three grades add up to 75% of the usual grades, so everyone has to work hard."
On the podium, a professor in his fifties smiled and looked at the students in the classroom, holding a stack of printed test papers in his hand.
This is the professor who teaches multivariate calculus in Class 1 of the Department of Physics. His name is Lin Yao. He is a professor at the School of Mathematics of Shanghai Jiaotong University. At the same time, because of his in-depth research on physics, he became their mathematics teacher.
When they heard the professor's words, the students present all pretended to wail.
Of course, although they are pretending, they are not pretending in their hearts.
Forget about unary calculus, it was already a matter of last semester, but this semester's multivariate calculus really made them feel the fear of being dominated.
The solution to the problem of multivariate calculus is basically to simplify it to unary calculus first, and then use the method of unary calculus to solve it. It can be said that the level of complexity is inherently higher.
So just the few classes they took this semester already made them feel like they were dying.
Not to mention the upcoming exam, which is sure to be another torture.
Of course, Lin Yao didn't care about the feelings of these students, so he asked the class representative to come up with a smile and began to distribute the test papers.
In the fourth row, on a seat next to the wall, Li Mu took the test paper from the students in front, and after taking one, passed it to the students in the back row.
For this exam, compared to others, he can say that he is not in a hurry at all.
This is the confidence that the computer in his mind gave him.
Unlike the people around him who immediately looked at the questions first, he took out a pen without haste, first wrote his class name and student number, and then looked at the questions.
First look at the question types, five multiple-choice questions, five fill-in-the-blank questions, and four major questions.
The multiple-choice questions and fill-in-the-blank questions are all five points, adding up to fifty points. For the four major questions, the first two are worth ten points, and the last two are worth fifteen points. The full score is 100 points.
And the time is also one hundred minutes, two classes plus ten minutes between classes.
The next step is to examine the questions.
At this time, the computer in my mind started to run rapidly again.
When the information of all the topics entered Li Mu's thinking, the computer in his mind also began to analyze these topics at the same time.
At the same time, the knowledge of multivariate calculus that he read twice in a day yesterday also flooded into his heart like a tide.
Until about half a minute later, the corners of his mouth curled up slightly.
Then I came to a conclusion: it's all quite simple.
Even simple is a bit too much.
This made him wonder, could it be because it was their first time to take the exam, and Professor Lin gave them a little water?
But he clearly remembered that the first quiz in one-dimensional calculus last semester stumped the whole class?
The thoughts in his heart did not affect his analysis of the test paper questions.
Picking up the pen, I wrote the option [C] in the box of the first multiple-choice question.
The answer to the first question has already been obtained from his analysis of the test paper just now.
Then comes the second question.
"Well...f(x,y)/x and f(x,y)/y are continuous at (x0,y0) for the function f(x,y) to be differentiable at point (x0,y0) is..."
"Obvious sufficient condition, choose A."
"Keep going."
With every stroke of the pen tip, each question is completed.
Even Li Mu doesn't need scratch paper anymore, because the computer in his mind is the best scratch paper.
I don't know how long it has passed.
Before he knew it, Li Mu had reached the last question of the fourth big question.
And because when he was doing the previous question, he had already deduced this question through multitasking, so he started to write it after getting it.
"Well, since D is a compact set and u is continuous on D, it can take a non-negative minimum value on D, and then..."
"So the proposition holds."
"OK, done."
Putting down the pen in his hand, Li Mu didn't even check it.
"Is there anyone who can't even solve this kind of problem?"
He shook his head.
Uh... probably not, right?
It feels like the fifteen points for the last big question are given away for free. The question is indeed interesting, but it is not too much.
There are quite a lot of good people in their class. He studied so hard last semester, and his final grades didn't even make it into the top ten.
Thinking in his heart, he also came back from the state of ecstasy.
But as he looked up at the time on the clock in the classroom, he was stunned.
Clam?
It's only been more than forty minutes?
"Jinglingling~"
The get out of class bell rang suddenly, as if it was answering Li Mu——
That's right.
It was only forty minutes.
Just one class!
Li Mu rubbed his face.
Dude, this seems a bit... little fast?