Mei Yi put down the painting in her hand and wrote on the blackboard: "The four points A, B, C, and D are used to represent the four areas in the title, and this problem can be transformed into the question of whether the seven lines can be drawn without repeating each stroke." ”

"If it can be drawn, then there must be an end point and a starting point in the figure, and the beginning and end point should be the same point, and because of the symmetry, the effect of starting from B or C is the same. If we assume that A is the starting and ending point, there must be an exit line and a corresponding entry line. ”

"Define that the number of lines entering A is the degree of in, the number of lines leaving the line is the degree of out, and the number of lines related to A is the degree of A, then the degree of out and the degree of entry of A are equal, that is, the degree of A should be even."

That is, in order to have a solution from A, then the degree of A should be even, and in fact the degree of A is 5, which is an odd number, so we can know that there is no solution from A. In the same way, if we start from B or D, since the degrees of B and D are 3 and 3 respectively, they are both odd numbers, that is, there is no solution to take them as the starting point. ”

Mei Yi turned around and said to Liuxi: "Liuxi, do you understand?" ”

Liuxi is talented and intelligent, and he almost turned over the "Beauty of Mathematics" written by Mei Yi, and he understood it after reading it for a while.

Many of the goblin students around her were from the Mathematics Department of Deep Springs Academy, and after staring at them for a while, they were like being empowered, and some couldn't help but cry out "ah". They all looked at the black-haired human teenager with incredulous eyes.

Who is he?

I look like I'm about the same age as us.

You know, this question has been asked for hundreds of years, and no one has ever been able to answer it. I don't know how many goblin scholars have died on this topic and died with hatred.

It only took him two minutes!

They couldn't help but feel unworthy for the elf scholars who had worked so this math problem.

Mei Yi looked at the crowd and found that Liuxi's mother hadn't appeared yet, so she said, "Anyway, there is still some time, so I'll do the second question, right?" In the second question, let me see how to calculate pi without circumcision...... Hmmm......"

Just when the onlookers thought Mei Yi was stumped, Mei Yi asked Liuxi, "Can the students of Deep Springs Academy understand calculus?" ”

Liuxi knew in his heart that Brother Meiyi could solve this problem. She said: "It's okay, Brother Meiyi, your books are sold in the Fairy Forest, and they are also available in the library of Deep Springs Academy, if you don't understand it, you can go to tutor it yourself." ”

Mei Yi lost her psychological burden, and wrote on the blackboard with chalk:

a

cta

x=x-x^3/3+x^5/5-x^7/7+...+(-1)^

x^(2

+1)/2

+1

When x=1,

π/4=1-1/3+1/5-1/7+....+(-1)^

1/2

+1)

π=4(1-1/3+1/5-1/7+1/9-1/11+.. +(-1)^

1/2

+1)

Writing this, Mei Yi said: "I won't expand the calculation part anymore, it's too time-consuming, I'll write the results I calculated before directly on it, you can verify it yourself—3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679......"

Mei Yi was still writing, and Liumei's voice suddenly sounded behind her: "Meiyi, Liuxi, the vegetables have been bought, let's go home for dinner." ”

"Okay." Mei Yi threw away the chalk in her hand, and pulled the tide through the crowd on the inner and outer three floors under the terrifying gaze of everyone.

Liumei led a bighorn deer carrying two baskets of vegetables on his back and asked, "What are you doing at the gate of Deep Spring Academy?" ”

Mei Yi said: "I didn't do anything, Liuxi took me to take a casual look, and then transferred to Deep Spring Academy." Aunt Mei, you've bought too much food, haven't you? ”

In the originally lively Goddess Square, when the goblin clan saw Mei Yi coming back, their eyes showed respectful eyes. Some enthusiastic fairy girls threw winks at Mei Yi one after another.

Liumei obviously felt that something was not right with the performance of the clansmen, so she said suspiciously: "Meiyi, you really didn't do anything?" ”

Mei Yi shouted, "Aunt Mei, what else can I do?" Liuxi has been looking at me. ”

Liumei smiled: "Well, that's right. Let's go. ”

* * *

Si Ye, the dean of Deep Springs, heard the sound of the roar at the entrance of the academy in the office, and felt a little upset, so he went out to take a look, and said to the onlookers, "What are you doing?" Why is it so noisy today? ”

When the students saw that it was the dean, they immediately became much quieter. A student said, "Dean, the Seven Bridges problem and the pi calculation problem have just been solved. ”

When Siye heard this, he said with a calm face: "You guys are too good at joking." How can it be? ”

When she walked to the blackboard and looked at the handwriting on it, she was stunned. After watching it back and forth a few times, she felt cold: "This problem can really be solved......

When she saw the solution to find pi, she immediately felt a headache. She was not from the mathematics department, and it took about an hour for a mathematics teacher who had taught her "The Beauty of Mathematics" to teach her some calculus knowledge, and she could barely understand the logic of the problem.

"Who solved these two problems?" Four leaves asked.

"It's a human." Some students said.

Four leaves chuckled in his heart.

"Not human! He has one eye that is golden. A student retorted.

Four Leaves chuckled twice in his heart.

"It's human! His hair is black and his left eye is black too! By the way, his name seems to be Meiyi......"

Four leaves of the heart said: No wonder. Then it is not surprising.

She asked the students, "Do you know where he went?" ”

Before the student could answer, the four leaves noticed the painting under the blackboard, picked it up and looked at it, and was so shocked that he almost didn't fall to the ground. She said in surprise, "Isn't this the Liuxi of Lady Liumei's family?" Who drew this? ”

The student said, "Dean, Lady Liumei called Liuxi and that human to go home for dinner. This is the human who painted it, and he also played a tune "To Miss Liuxi" in the Goddess Square, and I have never heard such good music. ”

The corners of the four leaves smiled crookedly, and he laughed unconsciously.

The students were stunned and a little confused.

You must know that since returning from the Tianlu Mountain Range, Dean Siye has lost all his spiritual abilities, and his health has not been very good, and he has never smiled. I don't know why I'm so happy today.

Shiba turned to the onlookers and residents and said, "Stop shouting 'that human' and 'that human', do you know who he is?" In the Tianlu Mountains, he was the one who saved us from the dragon, and even lost our right eye for it. His right eye was given to him by Master Esther. ”

"The "Anthology of Flower Spirit Fairy Tales", "Forty-Nine Nights" and "The Beauty of Mathematics" that you are crazy to pursue were all written by him, and the lord in "As You Wish, Your Lord" is based on him."

"He is only sixteen years old, he has been a teacher of the True Spirit Academy and the princess's tutor, and now he is the Grand Lord of Sombra City, and he has single-handedly saved the millions of residents of Sombra City, including more than 100,000 of our people. Our Fairy Forest also gives him the respect he deserves, okay? ”

All the goblins present were like lightning strikes, and they were stunned and motionless on the spot.

It turned out to be him?

It's not our fault, looking at his casual appearance, who would have thought what kind of big lord he was?

A student carefully picked up the painting, and just wanted to run away, Shiba asked, "What do you want to do?" ”

The student said, "Dean, I'm going to give Miss Liuxi ......"

Siye said with a cold face: "Stop!" Turn it back and hang it up in my office. Also, immediately copy the results of these two questions to Princess Liulian, and say that Meiyi has come to the Northern Fairy Forest! ”