bivariate

1. not comparablemathematicsHaving or involving exactly two variables.

   Our upper bound is the best possible, and it implies the existence of low-rank factorizations of positive semidefinite bivariate matrix polynomials and representations of biforms as sums of few squares.

   2016, Grigoriy Blekherman, Daniel Plaumann, Rainer Sinn, Cynthia Vinzant, “Low-Rank Sum-of-Squares Representations on Varieties of Minimal Degree”, in arXiv

   Synonyms: two-way

plural bivariates

1. mathematicsA polynomial or function with exactly two variables.