After solving her problem, Gu Jin also casually wrote an equation on the blackboard, but it was a quadratic equation.

Then he gave the chalk to Gu Yang and signaled her with his eyes to do the questions.

Gu Yang blinked, "Haven't you seen the quadratic equation yet?"

Gu Jin raised his chin slightly, proud and arrogant: "Draw inferences from one example. Do you know how to do this? Do you want me to teach you?"

Gu Yang thought to himself, although this little brat is a bit arrogant, he is still quite cute.

Gu Yang suddenly wanted to stretch out her claws to pinch Gu Jin's face. However, just as she was about to do so, Gu Jin reached out and pinched her face first.

Gu Yang was confused.

Gu Jin: "No?"

Gu Yang hummed, picked up the chalk to solve the problem, and wrote a college calculus problem on the blackboard.

It's time to show some real skills!

Sure enough, after she finished writing, Gu Jin looked at the question at a loss, his eyebrows were twisted together, and he stared at the question intently.

Gu Yang put his hands on his hips and said proudly: "How is it? You don't know how to do it anymore? Do you want me to teach you?"

Gu Jin stared at the question for a long time and didn't even understand what some of the symbols meant, so she frankly admitted that she really didn't know the answer.

She handed the chalk to Gu Yang: "Here, come here, tell me how to solve it."

Gu Yang twirled the chalk with her little fingers, and said proudly: "Call me sister."

Gu Jin remained calm: "What's your name?"

Gu Yang: "Sister."

Gu Jin nodded seriously: "Yes. From now on you will be my sister."

Gu Yang: “…”

Gu Yang's smile disappeared.

This little brat is only a few years old, how come he knows how to trick people?

Gu Yang, who acts like a sister to others everywhere: "..." was hinted at.

Forget it, she is essentially an adult and can't bother with this little brat.

It was childish of her to use a college question to embarrass a primary school student.

She picked up the chalk and wrote the steps on the whiteboard while explaining: "This question..."

Gu Jin listened carefully and did not interrupt Gu Yang during the conversation.

Gu Yang was a little surprised. Could it be that Quan understood?

Then Gu Jin asked a series of questions: "What do these symbols mean?"

Seeing that she was eager to learn, Gu Yang explained everything one by one.

Gu Jin also drew an ∞ symbol on the blackboard: "Infinity? Why do we use this symbol to represent infinity?"

Gu Yang picked up the waste paper on the podium, folded it into a paper strip, rotated it half a circle, and then connected the two ends and pinched them to make a simple Möbius strip. "This is called a Möbius strip. If someone walks on it, it will go along the path it sees and will go on forever. This road is endless.

And you see, this Möbius strip looks very similar to this infinity symbol, doesn’t it?”

Gu Jin took the Möbius strip from Gu Yang, ran his fingers along the paper strip, and found that it had indeed returned to the starting point, and his eyes became more interested.

"There is only one side! There is really no end. What if someone really falls into the Möbius strip?" Gu Jin frowned, looking serious, thinking about this problem seriously.

Gu Yang was slightly stunned.

If someone really fell into the Möbius strip...

Then he struggled forward, but eventually returned to the starting point, and the journey continued until he died, and he would never reach the end.

Gu Yang felt as if something flashed through his mind, but he couldn't catch it.

(End of this chapter)