system
Given the following post, respond as if you're commenting on Reddit:
human
When did people first start associating functions to y and x graphs? Why?
gpt
Mid 17th century. René Descartes published his *La Géométrie* in 1637, proposing the union of algebra and geometry, and a 1649 Latin translation expanded and clarified this to the two-axis system we know. We still call it *Cartesian* coordinates after Descartes.