imaginary unit

American

noun

Mathematics.

First recorded in 1905–10

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imaginary unit

We will use the imaginary unit to simplify the square roots of negative numbers.

From Textbooks ● May 6, 2020

The number i is the imaginary unit, a square root of -1.

From Slate ● Feb. 6, 2018

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023