The regular Chinese test papers in the morning gave the students confidence, and even when the math exam was approaching, the classroom was still full of chat.

The pressure of the college entrance examination and the selection examination have been put aside, from the new products of Gu Ming to the new heroes of a certain glory, the short summer vacation, carrying too many hopes and suppressing the desire of a semester, are all put into practice in words.

And Li Shen and Jiang Shan, the two of them, were silent, like eternal ice.

Jiang Shan is also thinking about what to do in the summer, what else can he do besides studying? In the past, she was a carefree person in high school, and she slept until she woke up naturally during the summer vacation, read novels, and walked around the community with milk tea, and spent it in a mess.

If only she didn't know Li Shen, she could still go around, both fulfilling and boring, round and round. Now she has to spend more time with her parents.

The exam bell rang rapidly, and Wu Bo walked in with the test paper.

As soon as he entered the door, he saw Jiang Shan and Li Shen at the front and back tables, no matter how he moved, his head kept turning to this corner.

"Students, start the exam, cheat and drop out directly, and now send out papers." He said aloud, his sharp eyes sweeping around.

He didn't quite believe in the promises of young people, and always felt that these two people would come back from the ashes.

Li Shen just smiled, his grades would definitely be good, but whether he could go back or not depends on Jiang Shan's reaction.

Just as he was pondering, the scroll in front of him was handed to Li Shen.

Jiang Shan held the test paper in his hand and handed it to the back without looking back. But after a long time, Li Shen didn't take it.

Her hands trembled, and the test paper swayed and swayed, making a gurgling sound, but Li Shen still fell into deep thought.

Jiang Shan couldn't help but turn his head and slap the table.

Li Shen withdrew from thinking at this time, and raised his eyes to the angry and timid face.

"It's so pretty."

Jiang Shan turned his head, and the ponytail shook Li Shen's face.

After all the test papers, answer sheets, and scratch papers were distributed, Li Shen could no longer see the flipped wrist, which was as white as frost.

He scribbled on his admission ticket and began to solve the problem.

At first, everyone solved the problem fairly smoothly, and they didn't even use scratch paper. But gradually, cold sweat began to break out on everyone's faces, the pen kept scratching out the conclusion, and the classroom was full of chaotic writing sounds.

Li Shen also found it difficult, but after studying mathematics for so long, the principles of high school things have long been clear, and they can be solved without college mathematics.

The classroom suddenly fell silent, and from time to time there was the sound of paper tearing, it turned out that a few students were too depressed, and the tip of the pen unconsciously tore the scratch paper.

It's just too hard.

The heads were buried deeper and deeper, and their hands were raised higher and higher, indicating that they needed scratch paper.

Wu Bo had been staring at Li Shen all the time, but he was also tired at the moment, handing the scratch paper to the people who needed it.

As the minutes passed, the air above the classroom was full of impetuousness.

Wu Bo looked at his watch and said helplessly: "There is still half an hour before the end of the exam." ”

Hearing this, everyone in the examination room broke out in a cold sweat, and a few people even threw away their pens, buried their heads in their elbows, and began to give up on themselves.

The confidence given by the previous language papers was swept away.

Wu Bo looked at this scene and couldn't help but sweat. This math test is a competition of difficulty, just to screen out students who can go to summer camp.

But looking at this scene, their school doesn't know how many places they can grab.

And those who rank high among the top ten schools will even be looked at by the personnel of the liberal arts program.

This examination room is randomly arranged, and there are several top students in it, but judging by their reactions, it is obviously not easy.

As for Li Shen and Jiang Shan, he had long lost hope.

He paced around the exam room, glancing at the test papers of the top students, all of whom were still stuck in the penultimate question, and there were blanks underneath.

Suddenly, a neatly written test paper with the steps of derivation densely written on the surface caught his attention.

The penultimate question has been solved, and the tip of the man's pen is still rustling, and the finishing touch is finally drawn, and with a "...... from this" is written, only the last question is left on the test paper.

Wu Bo also kept calculating in his heart, yes! Hurry up and do the last big question!

The man suddenly stopped his pen and took out a can of pilot ink, and the of the pen slowly rotated, and the ink was drawn up from it.

The man's movements were slow, as if he was performing a ritual, and he remained indifferent to the pained wails of the students around him and the paper kept turning over and over, and finally gently closed the lid of the inkwell.

Wu Bo was as anxious as an ant on a hot pot, how could anyone use a pen for the exam.

The man started writing, and the moment the tip of the pen touched the test paper, the ink blurred, and a little stain appeared on the answer sheet, and he immediately withdrew the pen.

Obviously, the pen that has just been filled with ink has not been wiped with the nib, and the ink remains too much.

Wu Bo couldn't help it, stepped forward, took out the crumpled paper from his coat pocket, took the pen, and wiped it, the pale golden tip of the pen shone in the sun.

And just as he was about to put the pen back into the man's hand, his hand froze in the air.

Li Shen!?

Li Shen was also a little confused, looking at Wu Bo's distorted face, he thought that he was going to make things difficult for himself again.

But Wu Bo just stuffed the pen back and muttered: "Be careful about the exam, don't use the pen in the future, waste time and be hypocritical." ”

But he still didn't leave, turned around, and walked behind Li Shen.

Li Shen also felt that gaze, like a man's back. But he still gathered his mind and looked at the last question seriously.

Let n≥3, the real numbers x1, X1, X3...... Xn meets X1 ≥ X2≥...... ≥ Xn，

X1+X2+.…+Xn=0，X1*X1+X2*X2+…+ Xn* Xn=n（n-1）

Find the maximum and minimum values of X1+X2.

It's hard, it can't be done.

The pen in his hand kept calculating on the scratch paper, and the originally snow-white scratch paper was suddenly covered with handwriting. Wu Bo immediately handed over a piece of scratch paper.

He looked at this problem and fell into deep thought, he used to be the leader of the mathematics competition group, but when he saw this problem, he had no clue.

He firmly believes that whoever can do this question will be able to get the first place in this mathematics exam, but unfortunately, Li Shen has no movement.

If you can get this first place, you will also be honored as a teaching director.

"There are still 15 minutes before the end of the exam, so hurry up." Wu Bo looked at his watch and spoke anxiously.

The sound of flipping through the test papers and checking in the classroom suddenly became louder, and they all gave up and chose to check the content in front of them.

Wu Bo was also in a complicated mood, on the one hand, he hoped that Li Shen would solve it quickly, which would be good for his teaching career; On the one hand, he felt that he would be slapped in the face, and in these two entanglements, Li Shen started to write.

According to Wu Bo's idea, it is necessary to set an Xa term, and the value of a is between 1 and n-1, which is done through inequality transformation and Cauchy inequality.

But Li Shen's solution is very familiar and unfamiliar, he did set item A, but after classifying and discussing and getting the first interval, Li Shen changed to an unfamiliar solution, which was so strange that it reminded him of his college days.

As the results of the final categorical discussion were written, the radio also sounded in a hurry.

Wu Bo took the answer sheet, flipped it over and over again, and made sure that the multiple-choice questions and the admission ticket were filled in correctly, and then he breathed a long sigh of relief.

Li Shen also packed up the pencil case, looked at Wu Bo, and asked with a smile, "Teacher Wu, how is it?" ”