The love of functions and derivatives

In the next month, the derivative will come to see the function every day after work.

"You don't have to worry about work. I will help you with what I can do for you. You just need to rest easy." Derivative said, "The person who asked for the college entrance examination has a research project to do recently, so he can't come to our high school math textbook." But he already knows about it, and he won't take it lightly."

Function nodded to show that he understood, and continued to lie on the bed and ate the preserved egg and lean meat porridge that Derivative fed him.

"Your porridge with preserved egg and lean meat doesn't have a pinch." Function began to flatter the derivative again, "Salty but not greasy and chewy."

"I want to eat this every day in the future, can you teach me how to do it?" Function resolutely bowed his head to the gourmet power, "Don't be ashamed to ask", and the derivative humbly asked for advice.

"It's easy," Derivative dug a mouthful of porridge from the bowl and brought it to Function's mouth without changing his expression, "Take out your phone—"

Function wrapped the porridge in the spoon in one gulp, swallowed it, and nodded to show that he had it.The function thought that the derivative was going to pass the video of himself making porridge to the function, but the derivative said——

"Order a certain group of takeaways, search for delicious porridge shops, and then place an order."

"Huh? You didn't do this?"

"Ah."

In the next second, the function realized a very important question: "No, you, do you still order takeaway?"

Derivative raised his eyebrows, and used body movements to show why he couldn't order takeaway.

Derivative arrives at the hospital on time every day like clocking in at work. It is impossible not to be moved by the function, and he gradually became familiar with Derivative, "Then I'll just say it, when I added you as a friend on QQ, I was caught by your sentence GG or MM' freaked out."

"Isn't that the usual way of greeting QQ netizens?"

Function suppressed a smile and explained, "That's the way netizens used to say hello more than ten years ago."

"Oh." Derivative said with a blank expression on his face, "Since I added you as a friend, it has been more than ten years since I logged into QQ last time."

The derivative may have guessed what the function will say next. After thinking about it, he added: "I re-applied for the QQ account you added a few days ago, so the avatar and screen name are more random. Because my original QQ account I forgot the password, and the security questions I set up are useless."

Function asked curiously, "Then what was your original online name?"

"I can't read it, but I can type it out for you to see." Derivative said.

Hearing the words, Function suddenly had a bad premonition, Derivative stretched out his hand holding the mobile phone in front of Function, and Function only saw a few large characters on the screen——

☆堙你↗譕爱卍.

"what happened?"

Function shook his shoulders, suppressed the corners of his mouth, and then restrained himself from making some strange sounds: "...It is very in line with the trend at that time."