- quadratick (obsolete)
From French quadratique (1765), from Latin quadrātus + -ique (English -ic), form of quadrō (“I make square”), from quādrus (“square”), ultimately from Proto-Indo-European *kʷetwóres (“four”), whence also Latin four.
quadratic (not comparable)
- (mathematics) of a polynomial, involving the second power (square) of a variable but no higher powers, as .
- (mathematics) of an equation, of the form .
- (mathematics) of a function, of the form .
quadratic (plural quadratics)
- (mathematics) A quadratic polynomial, function or equation.
Not to be confused with quartic (“degree four”). Both derive ultimately from Proto-Indo-European *kʷetwóres (“four”), with quadratic coming from “four-sided”, hence “square, two-dimensional, degree two”.