In the eyes of science students, once the complicated calculus formulas are combined, they become endless love stories. For example, "I am sin and you are cos. Don't ask for the sum of squares, just ask for tan. " The sum of squares of sin and cos is 1, and sin is divided by cos to get tan, which ranges from positive infinity to negative infinity, which can be understood as "the relationship between two people is infinite and immeasurable."