Early spring came, and it rained lightly.

As a result, I couldn't go out for two days on the weekend.

As for the party that Li Xijing asked.

Before Su Mu even had time to ask Yan Xiaoke's wishes, he had already forgotten everything.

When Li Xijing invited Su Mu again on QQ, he could only excuse himself with his busy studies.

Su Mu didn't lie.

He's been very busy with his studies lately.

Because after knowing that the Olympiad questions could be scored, Su Mu stayed at home for almost the whole weekend to study.

And have fun with it.

Su Mu never thought in his life that he could be so obsessed with learning.

Even, when he was ready to rest on Saturday night, he was a little surprised that he had earned more than 100,000 points in one day.

When I was obsessed with math.

In fact, time flies.

It's like spending time in math class.

But when it comes to the exam room, the two-hour math test always passes very quickly.

Before I even finished the questions, I had to hand in the papers.

Yan Xiaoke also came to Su Mu once.

Seeing him brush up on the questions again, Su Mu's mind was more determined to study secretly.

Su Mu worked so hard, she felt that she couldn't hold back.

It also automatically opened the struggle mode of the top student.

In this world, those who are more talented than you are not terrible.

The scary thing is that people who are more talented than you work harder than you!!

What's even more terrifying.

People who are both talented and harder than you are likely to have a demonic point system on them....

Su Mu has almost brushed the Olympiad questions in junior high school.

He also slowly found that these questions added less and less to his points.

Even if there are some particularly difficult questions occasionally, you can get a lot of points, but the overall efficiency is indeed reduced.

On Sunday, Su Mu was going to go to the bookstore to buy a high school Olympiad to see if he could improve some efficiency.

But by accident, I bought a book of advanced mathematics.

Originally, I just had the attitude of flipping through casually, but I didn't expect to be fascinated all of a sudden.

......

In the third week of school, the teaching process continues to gradually pick up.

At noon, Su Mu stayed at school as usual, ready to continue brushing up on the questions.

He is now studying the Lopida Law and Taylor's Formula in Advanced Mathematics, which is why Su Mu was directly attracted to this book.

Lopida's rule is a method of determining the value of the infinitive formula by finding the derivative of the numerator and denominator respectively and then finding the limit under certain conditions.

It is well known that the limits of the ratio of two infinitesimal or the ratio of two infinity may or may not exist.

Therefore, it is often necessary to find such limits in a form that can be calculated using limit algorithms or important limits.

Lopida's rule is a general method applied to this type of limit calculation.

Taylor's formula, on the other hand, is a formula that describes the value of a function near a point with information about it.

If the function is smooth enough, Taylor's formula can use these derivatives as coefficients to construct a polynomial to approximate the value of the function in the neighborhood at that point, given that the derivative values of the function at a certain point are known.

Taylor's formula can also give the deviation between this polynomial and the actual value of the function. Wenxin School

To put it simply, Lopida's rule is the big brother of the limit of functions, which is mainly divided into zero-to-zero and infinite-than-infinity, and as long as the problem meets the conditions, it is easy to draw conclusions.

And because there are many conditions for the law of Lobida, Taylor developed this little brother to solve some more troublesome problems.

Su Mu has been fascinated by these two formulas recently, these two formulas can cover almost most of the limit function question types in high school, and he feels that if he is proficient in using them, he can greatly speed up the progress of brushing scores.

"Su Mu, are you still studying?"

"Wow! Advanced Mathematics? Isn't this a college textbook? ”

"No wonder I said that your academic performance has improved so much so suddenly, it turns out that you work so hard in private."

Because there is still a lot to explore about the law of Lobida and Taylor's formula, Su Mu has been studying it for the past two days.

A crisp voice interrupted Su Mu's thoughts, he raised his head and found that it was Wang Shuting, a member of the Literature and Art Committee.

"It's okay, I'll just take a look." Su Mu smiled at Wang Shuting.

In the morning, he had already heard Yan Xiaoke say that this week the class would hold a blackboard newspaper about spring.

After Yan Xiaoke went home and finished eating, he would come over to help Wang Shuting later.

There were quite a few people in the classroom at noon today.

In addition to Su Mu brushing up on the questions, there were several other students who were also studying in the classroom.

"I heard my cousin say that college knowledge is difficult, can you really understand it?" Wang Shuting leaned her head over, glanced at the dense characters on Su Mu's draft paper, and unconsciously took two steps back.

"I guess I can understand a little bit." Su Mu nodded truthfully with a smile and explained: "In fact, the knowledge of the university is an expansion and supplement to high school, such as the Lobida law you are reading now, which can actually speed up the speed of solving problems." ”

"Sorry, big guy, for the interruption."

Wang Shuting covered her face and retreated.

She originally thought that Su Mu's academic performance had improved so quickly, probably because of reading these books.

But after a little glance, she felt that she was still more suitable for drawing the blackboard newspaper.

"Su Mu, can you show me your book?"

Wan Xin, who was on the other side of the classroom, was also attracted by the conversation between the two.

During this winter vacation, Wan Xin had enough to sign up for two training classes, and when he heard that Su Mu was studying in the classroom at noon, he decided to make good use of this time.

Wan Xin wants to take advantage of this semester to do a good job, and he can also impress the classmates.

Mathematics is Wan Xin's dominant subject, and even in this class, he is a few points better than Yuan Haoyu.

Seeing that Su Mu was pretending to look at advanced mathematics, he was also suddenly interested.

"Do you want to see it?" Su Mu was a little surprised, Wan Xin didn't usually talk to him much.

However, seeing that Wan Xin had already walked towards him, Su Mu replied: "Then you wait a little, I will analyze this formula and show it to you." ”

Su Mu is now analyzing the application of a Lobida rule in high school mathematics.

Let the function f(x)=e^x-1-x-ax^2

If a=0, find the monotonic interval of f(x).

If x≥0 and f(x) ≥ 0, find the range of the value of a.

Wan Xin came over and took a look.

A little puzzled, he asked suspiciously, "Isn't this the content of high school?" ”

"It's just a common function problem."

Su Mu nodded, and explained: "I'm studying this right now, and it seems that I can save a lot of steps with the law of Luobida." ”

This problem can actually be solved very well with the 00 model, first assign the value to the equation is an increase function, and then you can directly use (x→0)lime^x-x-1x^2=(x→0)lime^x2x=(x→0)lime^x2=12

"Then you can directly conclude that the value range of result A is from minus infinite to 12, which is several times faster than the method that the teacher usually teaches."

Wan Xin was stunned, his mouth slightly open.

What is Su Mu talking about?

The value range is out?

.......