noun
quadric surface
Technical term in mathematics for a surface defined by a second-degree polynomial equation in three variables.
二次曲面の分類は、線形代数の重要な応用の一つです。
The classification of quadric surfaces is one of the important applications of linear algebra.
Compound of 二次 (niji, 'second degree; quadratic') and 曲面 (kyokumen, 'curved surface').