The Princess and the Tramp

In 1650, 52-year-old Descartes met 18-year-old Swedish Princess Christine on the street of Stockholm. 

At that time, the poor, penniless Descartes lived a life of begging, and all his possessions were rags and a few math books he had with him. 

Show a sense concinnity and harmony when in our short mother of the bride dresses . There are arrivals in the latest fashion trends.

Descartes, who is noble by nature, never asks for alms from passers-by. He just silently bows his head and writes on a piece of paper, devoting himself to his mathematical world. 

On a quiet afternoon, Descartes sat in the street, as usual, basking in the sun to study mathematical problems. 

He is so addicted to the mathematical world, the passing crowd around him, the noisy procession of carriages and horses. 

Can't disturb him. 

Suddenly, someone came up to him and patted him on the shoulder. "what are you doing?" 

Turning his head, Descartes saw a young and beautiful eyelid, a pair of clear eyes such as a blue lake, beautiful, long eyelashes blinking, looking forward to his response. 

She is the little princess of Sweden, Christine, the king's favorite daughter. 

She squatted down, took Descartes' math book and draft paper, and talked to him. 

During the conversation, he found that the little girl had a quick mind and a strong interest in mathematics. 

After saying goodbye to the girl, Descartes gradually forgot about it and still sat on the street every day to write and draw. 

A few days later, he was unexpectedly informed that the king hired him to be the princess's math teacher. 

Full of doubt, Descartes followed the informing guards to the palace, and while waiting in the drawing-room, he heard a silver bell of laughter from afar. 

Turning around, he saw the girl he had met in the street the day before yesterday. 

In a hurry, he bowed his head and saluted. 

From then on, he became the princess's math teacher. 

The princess's mathematics advanced by leaps and bounds under the careful guidance of Descartes, and they began to become intimate with each other. 

Descartes introduced her to his new field of study-Cartesian coordinate system. 

Through it, algebra and geometry can be combined, which is the embryonic form of analytic geometry founded by Descartes in the future. 

Under the leadership of Descartes, Christine walked into the wonderful world of coordinates, and she was fascinated by curves. 

The inseparability of each other every day also makes them love each other. 

In the romantic country of Sweden, pure and beautiful love is sprouting quietly. 

However, it was not long before their love spread to the king's ears. 

The king was furious and ordered Descartes to be executed immediately. 

At the begging of Christine, the king banished him and the princess was placed under house arrest. 

At that time, the Black Death was prevalent in continental Europe. 

Soon after the frail Descartes returned to France, he fell seriously ill. 

In the days when his life entered the countdown, what he missed day and night was the warm smiling face he came across on the street. 

He keeps writing to her every day, looking forward to hearing from her. 

However, these letters were intercepted by the king, and the princess never heard from him. 

After Descartes sent Kristen his thirteenth letter, he left this world forever. 

At this time, the little princess under house arrest is still wandering in the corridor of the palace, missing her lover from afar. 

There is not a single sentence in this last letter, only one equation: Ryoga (1-sin theta). 

The king could not understand and thought that there was a secret between two people in the equation, so he summoned mathematicians from all over the city to the palace, but no one could solve the function. 

He couldn't bear to see his beloved daughter moping every day, so he gave her the letter. 

Kristen, who got the letter, was so overjoyed that she immediately understood her lover's intention, found paper and pen, and began to draw the equation. A heart-shaped pattern appeared in front of her eyes, and Christine could not help but shed moved tears. this curve is the famous "heart-shaped line". 

After the king died, Christine succeeded to the throne. After ascending the throne, she immediately sent someone to France to find her sweetheart. However, she received the news of Descartes' death, leaving a lasting regret. 

This alternative love letter, which is famous all over the world, is still preserved in the memorial of Descartes in Europe.