The advertisement of Baisui Mountain is a metaphor for the love story between French philosopher Descartes and Swedish princess Christina.
1650, Descartes, a poor French mathematician, was sitting in the street, thinking hard about a math problem. Just then, he met the Swedish princess Christina, who also loved mathematics. At that time, Descartes had nothing on him except a few math books, but in this way he became the princess's math teacher.
The princess was diligent, and Descartes gave everything to each other. The two faced each other day and night and finally fell in love. Descartes is 52 years old and Christina is only 18 years old. However, the disparity in age and status makes it difficult to get other people's blessings even in a romantic and free country like Sweden.
Not long after, the relationship between the two let the king know. In a rage, the king wanted to condemn Descartes. At the princess's bitter request, this was changed to deportation and the princess was also under house arrest. Descartes, who returned to France, thought hard about the princess. At the end of his life, he decided to write to the princess every day, but these letters were stopped by the old king and did not reach the princess.
Descartes died after writing the last letter to the princess. There is only one mathematical formula for this letter: r=a( 1-sinθ).
The king was very curious. He invited many mathematicians to solve the mystery, but it was difficult to solve it. Finally, he gave it to the princess. The princess quickly solved the mystery by using Professor Descartes' method, which was an impressive heart-shaped pattern composed of curves. Only then did she know that her beloved had already passed away, and she burst into tears.
parsing process
R = A (1-sinθ) This function has two variables, which can be assigned to A and then solved. The function image is a heart-shaped line. This equation is also called "Cartesian love coordinate formula". As shown in the figure, the images are a= 1, a=2 and a=3 respectively.
The arc roundly depicts the shape of the lover's heart and finally returns to the starting point. Minimalist formula, complete cycle, eternal love, which became the so-called Cartesian coordinate system.