discriminant

American  

[dih-skrim-uh-nuhnt] / dɪˈskrɪm ə nənt /

noun

Mathematics.

1. a relatively simple expression that determines some of the properties, as the nature of the roots, of a given equation or function.

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discriminant British  

/ dɪˈskrɪmɪnənt /

noun

1. an algebraic expression related to the coefficients of a polynomial equation whose value gives information about the roots of the polynomial

   b² – 4ac is the discriminant of ax² + bx + c = 0

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Other Word Forms

• discriminantal adjective

Etymology

Origin of discriminant

First recorded in 1830–40; from Latin discrīminant-, stem of discrīmināns “separating,” present participle of discrīmināre “to divide up, separate,” verb derived from discrīmen (stem discrīmin- ) “separating line, distinction,” from discrī- (variant stem of discernere; discern ) + -men, noun suffix

Explanation

A discriminant is a mathematical expression used to determine some properties of a larger equation or function. Outside of math, a discriminant is a property that distinguishes something from something else, or an adjective meaning "having good judgment." In algebra, the discriminant is the part of the quadratic formula that is under the square root symbol. Plug in the numbers from a quadratic equation to determine how many and what type of roots (solutions) the equation has. More generally, a discriminant is any distinguishing attribute, as in "the discriminant between yellow and black labs is fur color." Adjectivally, a discriminant person is discerning: If your pals are always getting into trouble, perhaps you should be more discriminant when choosing friends.

Example Sentences

The newly applied method uses both traditional phylogenetic analysis, discriminant analysis as well as machine learning.

From Science Daily • Mar. 12, 2024

That track record makes it “a perfect discriminant for whether there is going to be a recession or not,” he said.

From New York Times • Oct. 26, 2022

Before you to find the values of the x-intercepts, you may want to evaluate the discriminant so you know how many solutions to expect.

From Textbooks • May 6, 2020

The discriminant negative, so there are no x-intercepts.

From Textbooks • May 6, 2020

The groups simply isomorphic with the totality of the projective transformations which change a quadric of non-vanishing discriminant into itself.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 6 "Groups, Theory of" to "Gwyniad" by Various