discriminant
UK[dɪˈskrɪmɪnənt]US[dɪˈskrɪmɪnənt]
n
A mathematical expression whose value determines properties of a polynomial equation, especially whether its roots are real, repeated, or complex.
Morpheme Breakdown
dis
crimin
ant
dis
apart
crimin
to judge, to separate
ant
noun suffix
Etymology
The word 'discriminant' is built upon the Latin verb discriminare, meaning "to divide or separate." This verb itself derives from discrimen, a noun for a dividing line or distinction, which originates from cernere, a foundational Latin verb meaning "to sift, separate, or decide." The core semantic thread from "to sift apart" evolved into the concept of making distinctions. In mathematics, the term was adopted in the 19th century to denote a specific formula that "separates" or distinguishes between different types of solutions (like real or complex roots) of a polynomial equation, perfectly encapsulating its etymological logic of separation and judgment.
Analysis
Structure: dis (apart) + crimin (to judge, to separate) + ant (noun suffix)
dis: Latin prefix meaning "apart, asunder, away."
crimin: From Latin crimin-, stem of crimen (judgment, decision, accusation), from the verb cernere (to sift, separate, decide).
ant: Latin suffix -ant- (present participle ending), used here to form an agent noun.
Examples
The discriminant of a quadratic equation is calculated as b² - 4ac.
If the discriminant is positive, the equation has two distinct real roots.
A zero discriminant indicates that the parabola touches the x-axis at exactly one point.