imaginary number

American  

noun

Mathematics.

1. Also called imaginary, pure imaginary number.  a complex number having its real part equal to zero.

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imaginary number British  

noun

1. any complex number of the form i b , where i = √–1

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imaginary number Scientific  

/ ĭ-măj′ə-nĕr′ē /

1. A type of complex number in which the multiple of i (the square root of −1) is not equal to zero. Examples of imaginary numbers include 4 i and 2 − 3 i, but not 3 + 0 i (which is just 3).

2. See more at complex number

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Etymology

Origin of imaginary number

First recorded in 1905–10

Example Sentences

That infinities, infinitesimals, imaginary numbers or other unusual number spaces can be difficult to describe may not seem too surprising.

From Scientific American

Our finding means that imaginary numbers are an essential ingredient in the standard formulation of quantum theory: without them, the theory would lose predictive power.

From Scientific American

It's hard to wrap your head around imaginary numbers.

From Scientific American

“What do you know about imaginary numbers, plane geometry, and vector algebra, Jake?”

From Literature

This is only true if you accept imaginary numbers as well as real numbers.

From Literature