Soon, the math teacher, Mr. Zhen, was invited over.

Teacher Zhen is not only a mathematics teacher, but also the mathematics director of the entire Zhongnan No. 1 Middle School. It was not easy to become a teacher in a provincial key high school like Zhongnan No. 1 Middle School, and it was also the mathematics director, which is enough to show his ability. He is quite famous in the entire Zhongnan City education circle.

After learning about the situation, Teacher Zhen agreed because he also wanted to know whether Qin Wudao got nearly full marks in the math test paper based on his own strength.

You should know that the math papers for the second simulation test are not ordinary difficulties.

Teacher Zhen quickly wrote a difficult problem on the blackboard: "It is known that a and b are real numbers, and the functions f(x)=x^3ax, g(x)=x^2bx, f'(x) and g'(x) are derivative functions of f(x) and g(x). If f'(x)g'(x)0 is always true in the interval i, then f(x) and g(x) are monotonic in the interval i. Now let a < 0, and ab, if the functions f(x) and g(x) are monotonic in the open interval with a and b as the endpoints, find the maximum value of |a-b|."

As soon as they saw the question, all the students subconsciously answered it on a blank paper.

Zhang Yue is the same.

The same is true for top students like Li Ziwei and Mu Qingyan.

Only Qin Wudao looked at the topic lightly, motionless.

About ten minutes later, Qin Wudao was still motionless on the table.

Li Ziwei, Mu Qingyan and several top students who are more powerful in mathematics stopped and obviously got the answer.

At this time, Zhang Yue also raised his hand and spoke: "Teacher, I've solved the answer."

He also submitted all the steps and answers to the problem.

The math teacher looked at it for a moment and nodded slightly. It was obvious that Zhang Yue's answer was found.

He immediately looked at Qin Wudao and said, "Where are you, Classmate Qin?"

Qin Wudao spoke: "I have also solved the answer."

Everyone was stunned. You didn't have an answer at all. How could you know the answer?

The math teacher also frowned slightly and said, "What is the answer?"

“1/3!”

Everyone was stunned, and the math teacher showed a little surprise: "How did you solve it?"

Obviously, Qin Wudao's answer is correct.

However, Qin Wudao has not answered it on paper since the beginning, and it is impossible to know the answer. Has he seen the answer?

Many students were puzzled and believed that this view was the most likely.

Zhang Yue stood up and said, "Qin Wudao, you have read the answer again."

Qin Wudao sneered: "The question was randomly posted by the math teacher. I didn't know in advance. Do you suspect that Teacher Zhen colluded with me?"

Zhang Yue's expression changed and he hurriedly said, "I dare not doubt Teacher Zhen, but how do you know the answer? You haven't analyzed it yet."

Qin Wudao said lightly: "Because I analyzed it in my mind."

"impossible!"

Everyone doesn’t believe it, and analyze it in their minds, is that still human?

Qin Wudao stood up, walked directly to the blackboard, picked up the chalk and wrote it, and explained: "The first thing is to find the lead, and the solution is f'(x)=3x^2a     g'(x)=2xb

Then, from the conditions, we can see that in the interval, there is (3x^2a)(2xb)0."

"Then draw the picture f'(x)=3x^2a, which is a parabola with an vertex (0, a) and an opening upward."

"The same draw g'(x)=2xb is a straight line."

"Because the question is not given to which one is bigger, a and b, the question is a little more complicated."

"It can be divided into two situations. First, assume b is greater than a, so the interval is (a, b). According to the image, we can know that the intersection point between the straight line and the x-axis is (-b/2, 0). If b is greater than 0, so b is greater than -b/2. In the interval (-b/2, 0), g'(x) is greater than 0, and f'(x) is less than 0, so b cannot be greater than 0."

"When b is not greater than 0, the intersection point (-b/2,0) is on the right side of the y axis, or on the y axis (b=0), then g'(x) is always less than or equal to 0 in the interval (a,b), which means that f'(x) is also always less than or equal to 0 in (a,b). Through the image, we can find that when x is less than -√-a/3, f'(x) is greater than 0, so a must be greater than or equal to -√-a/3, and the solution is that a must be greater than or equal to -1/3. Therefore, the range of a is [-1/3, 0), and the range of b is (a, 0], so the maximum value of |a-b| is 1/3."

"When b is less than a, then b is less than 0. The same is true for the diagram, and the solution is greater than or equal to -1/3, and b is greater than or equal to -√-a/3, and the result is that the solution cannot be continued."

Zhang Yue couldn't help asking: "Why when x is less than -√-a/3, f'(x) is greater than 0, so a must be greater than or equal to -√-a/3?"

Qin Wudao explained: "First, the second one is, since g'(x)=2xb and the x-axis intersection point is (-b/2, 0), from the image, we can see that when x is greater than -b/2, g'(x) is greater than 0, and then let b be greater than 0, then -b/2 is less than 0 and less than b, which means that in the interval of (-b/2, 0), g'(x) is greater than 0, and from the image, we can see that in the interval of (-√-a/3, 0), f'(x) is less than 0, which means that no matter what the relationship between a and b is, there must be an interval on less than 0, g'(x) is greater than 0, and f'(x) is less than 0, so b must not be greater than 0. So b is less than or equal to 0. As for why b is greater than a, I set it. At the beginning, I directly set b is greater than a. Therefore, there is an interval as (a, b).

"First, since it has been proved above that b is less than or equal to 0, it means that -b/2 is greater than or equal to b. Combined with the image, it can be seen that in the interval (a,b), g'(x) is always less than or equal to 0, so there must be (a,b), and f'(x) is always less than or equal to 0, so a must be greater than or equal to -√-a/3, because as long as a is less than -√-a/3, it means that in the interval (a,b), the x value can be taken so that f'(x) is greater than 0."

"Because the sizes of a and b are not given in the question, when b is smaller than a, the specific value cannot be obtained, but through discussion, it can be proved that the maximum value is less than 1/3. As a result, when the two situations are combined, the maximum value is 1/3."

Although it was only one question, all the students basically believed that Qin Wudao really answered it with his own strength.

It is not necessary to say how powerful a person who can answer the answers to math questions in his mind and can still calculate it without giving the size of a and b.

Teacher Zhen’s eyes at Qin Wudao were full of praise. He was a genius!

Zhang Yue's face changed again and again. He would never allow this to happen. Please ask the teacher to continue to ask a few major questions.

He wants to overwhelm Qin Wudao in the following big questions.

He didn't believe that Qin Wudao was really that powerful.

However, in the following several major questions, Qin Wudao quickly answered them before Zhang Yue had already answered the steps.

Even this bet attracted the attention of teachers in other subjects, especially Qin Wudao, the first student in the new grade who jumped into the leap. These teachers also doubted his strength. Even if there was no evidence, they were quite suspicious and participated.

However, whether it is English, Chinese, comprehensive, or teachers in various subjects, Qin Wudao answered them quickly and perfectly one by one.

Looking at Zhang Yue whose face turned bluer, Qin Wudao sneered, who is he? A generation of undefeated war god, not only has amazing combat power, but also wise. Otherwise, why would he be able to surround the world in his previous life, making great powers bow down. Do you really think his mind is simple?

In his eyes, the so-called mathematics is just ordinary. If he hadn't been too lazy to waste time studying, it would not be impossible to solve the so-called mathematical conjectures, and it would be comparable to a mere Zhang Yue.

Qin Wudao looked at Zhang Yue and said coldly: "You lost."

Zhang Yue looked ugly, but he had to admit: "Yes, I lost, I admit you didn't cheat."

After saying that, he was about to go back, but Qin Wudao grabbed him with one hand and raised his eyebrows: "That's all?"

Zhang Yue panicked and said, "What else do you want?"

"I am willing to accept the loss of the bet, and I lie on the ground and bark three times!" Qin Wudao said lightly.

Zhang Yue's face changed color on the spot, and he said with hatred: "Qin Wudao, don't be too cruel and do it. Stop it in time, so you can meet again in the future."

Qin Wudao sneered: "I originally planned to do this, but you insist on forcing yourself, but I can't blame me. Lean down and learn to bark, otherwise don't blame me for taking action in person."

Feeling the severe pain from the point where his arm was caught, as if his arm was about to be broken, Zhang Yue's complexion changed.

He gritted his teeth and looked at the teacher quickly, hoping that the teacher would come forward.

But after this incident, Teacher Zhen admired Qin Wudao very much. He could solve the answer by using mental calculations, which was definitely a material that could be made.

And after understanding, I knew that Zhang Yue had taken the lead in this matter, so I naturally would not help.

The head teacher Li Shi could only frown slightly and said, "Class Wudao, this matter--"

He doesn't want the students to make such a fuss, after all, everyone has a fight.

Qin Wudao said coldly: "Teacher, you also see that it is not that I am willing, but that Zhang Yue repeatedly questioned me and made a bet with me. Now that he lost, he would naturally be willing to accept the loss. Otherwise, it would be spread. Everyone in Zhongnan No. 1 Middle School thinks I am easy to bully."

Li Shi sighed and walked out of the classroom, not wanting to see that scene happen.

Teachers from other subjects also left one after another.

Zhang Yue's face turned pale on the spot. He really wanted to bark in front of the whole class, and his face was lost.

"Qin Wudao, do you really want to be so cruel?" Zhang Yue was still unwilling to accept it.

"Let's go down."

Qin Wudao was too lazy to talk nonsense, pressed one hand on his shoulder and exerted a little force.

Bang--

Zhang Yue fell to the ground uncontrollably and was about to stand up in anger, but Qin Wudao stretched out one foot and pressed it on the air above his head, and said coldly: "If you don't fulfill your promise today, I will take action myself, but I can tell you, if I take action, you will not be as simple as lying down and learning to bark at the dog."

There is no lack of threat in the words.

Zhang Yue's face changed again and again. He knew that Qin Wudao's martial arts value was very abnormal. It was rumored that even Xiang Rong and Zeng Jianneng were not opponents in the Taekwondo Hall. If he resisted, he would only ask for trouble.

He had no choice but to learn to bark in humiliation: "Wow, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool, wool,

"Remember, don't provoke me next time you're fine, you can't afford to provoke me." Qin Wudao said coldly. With his sunny and handsome face, he was more evil and charming, but he was even more handsome and eye-catching, which made many girls quite moved.

Li Ziwei looked at him deeply.

After Qin Wudao left, Zhang Yue stood up with an ugly face and returned to his desk.

This time, he lost all his face.
Chapter completed!