Night----

"Knock knock......" There was a knock on the door......

"Come in." Yi Chen said.

"Xiaochen, I'm going to your school for a meeting today." Yi Mu looked at Yi Chen, who was reading a book, and said calmly, and silently put a glass of milk next to him.

"The principal and all the teachers have a good impression of you, this fight, my mother can not investigate it, according to what I heard you fought for a girl?" Yi Mu asked in a tentative tone.

"Hmm," Yi Chen said lightly.

"Oh...... Can you bring her home for dinner tomorrow? Yi Mu asked cautiously.

"Huh?" Yi Chen turned around and looked at Yi Mu and said suspiciously.

"Oh...... Mom doesn't mean anything else, no, usually mom is out talking about business, this time I finally came back, I just want to see that girl, after all, you, you have been a person since you were a child, this time you finally have a group of friends, and fight for other girls, mom is not curious" Yi's mother said gently.

"Well, then I'll ask her tomorrow." Yi Chen said.

"That's great, you have to take it home for a meal, it can't be too late...... emm…… Then tomorrow at noon, is that okay? Yi's mother asked tentatively.

"Hmm," Yi Chen said calmly.

Day 2----

"Xiao Dandan, quickly lend me your math homework to copy" Shen Yu's voice came from the classroom early in the morning.

"In the second compartment of the school bag, you can take it yourself," replied simply.

"Okay, love you, mua~" Shen Yu grinned.

"But I didn't write the last question, when Yi Chen came over, I asked him how to write," said simply.

"Then you ask, I won't write the last question, I can't do it anyway," Shen Yu said indifferently.

"Eh, he's here," said Yi Chen, who was about to walk in after looking at the door of the classroom.

"Me? What's wrong? Yi Chen heard this.

"Oh, I can't write that math problem, I don't want to ask you," he said simply.

"Oh, then come here" Yi Chen put down his schoolbag and picked up the math homework book, and said calmly.

"Bring the math book," Yi Chen said.

"This ...... Yuyu is copying it, just use yours......" said simply.

"Hmm......" Yi Chen glanced at Shen Yu, who was frantically copying his homework, and replied lightly.

"∵ f(x)=-f(x+2), ∴f(x+2)=-f(x+4), ∴ f(x)=f(x=4). Variant: In the same way, ∵ to all ......" Yi Chen took the draft paper and quickly wrote......

“emm…… So what does f(x) ultimately prove? He asked, staring at the dense numbers and letters on the sketchbook.

"Look, ∵ for all x∈R, f(x+2)=-1/f(x), ∴ for all x∈R,f(x)≠0, ∴f(x+4)=-1/f(x+2)=f(x). Got it? Yi Chen looked at the simple man who was biting the tip of the pen and frowned and asked.

"Probably...... Got it......" said simply uncertainly.

"What do you mean?" Yi Chen looked at it and asked simply.

"emm......" is a simple stop......

"Need I say it again?" Yi Chen asked.

“emm…… Say it again," said Simply scratching his head.

"∵ f(x)=-f(x+2), ∴f(x+2)=-f(x+4), ∴ f(x)=f(x=4). Variant: Similarly, ∵ for all x∈R, f(x+2)=-1/f(x), ∴ for all x∈R, f(x)≠0, ∴f(x+4)=-1/f(x+2)=f(x)...... Got it? Yi Chen took the pen and wrote carefully on the scratch paper again, and continued to look at the simple question.

"Well, I see, thank you," said simply, scratching his head embarrassedly.

"It's okay, by the way, are you free at noon?" Yi Chen asked.

"Yes, what's wrong?" Tilting his head briefly, he asked.

"Ahem...... My mom asked me to take you home for dinner. Yi Chen said with a serious face.

"Huh? Are you kidding me? Simple asked with a confused face.

"No, are you going?" Yi Chen said.

"Uh...... OK...... But why did your mother want you to take me home for dinner? Simple said with a blank face.

"It's nothing, my mother said that it was the first time I fought for a girl, and I was curious to see it," Yi Chen said with a calm face.

"Oh...... Your mom...... Won't blame me for hurting you, please parents, write a review......" stammered simply, embarrassed......

"No, he just wants to meet you," Yi Chen continued to say calmly.

"Oh......" replied simply.

Class----

"What do you say? Yi Chen wants to take you home for dinner?! Shen Yu said with a look of surprise.

"Shh......h You whisper," he said, looking around nervously.

"Yo, this is the rhythm of meeting parents...... Hehe......" Shen Yu looked at simplicity with a wicked smile.

"No, his mother just wanted to meet his friends......" said simply uncertain......

"Oh, it's to see your girlfriend, otherwise why don't you bring us with you, I wish you a happy meal with your mother-in-law at noon......" Shen Yu said solemnly.

"No, no...... Alas...... It's just ...... "I want to talk and stop, I don't know what to say......

"Okay, the explanation is a cover-up, the cover-up is the truth, good luck~" Shen Yu smiled.

Midday----

Yi Chen's ......

"Knock knock......" There was a knock on the door......

"It's coming......" a woman's voice sounded......

"Click" The door opened, and a dignified and elegant woman stood inside the door.

"Hello Auntie," she said simply and politely.

"Mom." Yi Chen said lightly.

"You're Xiaochen, come in," Yi Mu looked at and said gently.

"Please sit down, don't be restrained, Xiao Chen, go pour a glass of water for your classmates" Yi Mu motioned to sit down simply, and smiled gently at Yi Chen.

"Okay," Yi Chen replied.

"Simple classmate, right?" Yi Mu asked gently.

"Hmm," replied simply, smiling.

"Can I call you Shanshan?" Yi Mu asked cautiously.

"Yes, that's what my family calls it," replied simply and politely.

"Alone, do you know why Auntie wants Xiaochen to take you home for dinner this time?" Yi Mu asked gently.

Could it be because he fought for me? His mother was angry? Think simply. Of course, she would definitely not say these thoughts, so she simply and gently shook her head and said, "I don't know." ”

"Ah, what about me, Xiao Chen divorced his father when he was very young because of his incompatible personality, for many years, I have raised him alone, but I actually don't have much time to accompany him, rarely go home, are outside to start a business, talk about cooperation, so Xiao Chen He is used to getting along alone for many years because of family factors, and never communicates with others. This time, I'm also a little surprised, Xiao Chen actually fights for girls, it's really a strange news, so ah, I just want him to take you home to see, maybe this time it's a little sudden, don't you mind" Yi Mu said with a kind of annoyance.

"Auntie, it's okay, this time it's just an accident, everyone is friends, now Yi Chen has a lot of friends, he is very popular, and his grades are also excellent, everyone only praises him and does not criticize him, he is no longer the previous Yi Chen." He replied simply and seriously.

"That's good, thank you friends for taking him out of his old self and becoming a new self." Yi Mu smiled gently.

At this time, Yi Chen in the corner stopped there with a water cup and listened carefully, the corners of his mouth rose slightly......