imaginary number

noun

Definition of imaginary number

: a complex number (such as 2 + 3i) in which the coefficient of the imaginary unit is not zero

called also imaginary

— compare pure imaginary

Examples of imaginary number in a Sentence

Recent Examples on the Web

The symmetries of these matrices usually guarantee that imaginary numbers cancel out and the eigenvalues are real, so that these matrices make sense as descriptions of physical systems. Quanta Magazine, "Physicists Attack Math’s $1,000,000 Question," 4 Apr. 2017 If imaginary numbers have always seemed strange to you, prepare for a change in perspective. Quanta Magazine, "How to Find Simple Treasures in Complex Numbers," 14 Feb. 2019 For example, the solutions to x5 = 1 are five points on a circle when plotted onto a graph comprised of real numbers along one axis and imaginary numbers on the other. Davide Castelvecchi, Scientific American, "“Grand Unified Theory of Math” Nets Abel Prize," 20 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'imaginary number.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of imaginary number

1798, in the meaning defined above

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Last Updated

14 Sep 2019

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Time Traveler for imaginary number

The first known use of imaginary number was in 1798

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More from Merriam-Webster on imaginary number

Britannica.com: Encyclopedia article about imaginary number

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