Commentaries on Apollonius' Conics
Late 4th - Early 5th Century AD
Hypatia is known to have written a commentary on Apollonius of Perga's "Conics", which deals with the properties of conic sections (ellipses, parabolas, and hyperbolas). Although the commentary itself is lost, its existence is confirmed by other historical sources. This demonstrates her deep understanding of advanced geometry.