1637Reputable sourceWell documented
Descartes and Analytic Geometry
On the timeline · around 1637 · The Modern Age
What happened
In an appendix to his Discourse on Method (1637), the French philosopher and mathematician René Descartes fused algebra and geometry. By pinning points to numbers with coordinates — the x and y axes we still call Cartesian — he showed that geometric shapes could be written as equations and equations drawn as curves.
Why it matters
Analytic geometry united two branches of mathematics into one powerful language and gave later thinkers the framework they needed to invent calculus. Its coordinate system underlies everything from physics and engineering to computer graphics.