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complex number

American  

noun

  1. a mathematical expression (a +bi ) in which a and b are real numbers and i 2 = −1.


complex number British  

noun

  1. any number of the form a + i b , where a and b are real numbers and i = √–1 See number

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

complex number Scientific  
/ kŏmplĕks′ /
  1. A number that can be expressed in terms of i (the square root of −1). Mathematically, such a number can be written a + bi, where a and b are real numbers. An example is 4 + 5 i.


Etymology

Origin of complex number

First recorded in 1825–35

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

We had observed that, in such a scenario, which physicists call a quantum network, the Pál-Vértesi-McKague-Mosca-Gisin method could not reproduce the experimental outcomes predicted by complex number quantum theory.

From Scientific American Apr. 24, 2023

To divide complex numbers, multiply both the numerator and denominator by the complex conjugate of the denominator to eliminate the complex number from the denominator.

From Textbooks Dec. 1, 2021

Before multiplying, each square root of a negative number must be written as a complex number.

From Textbooks May 6, 2020

The standard form of a complex number is a + bi, so this explains why the preferred form is = bi when b > 0.

From Textbooks May 6, 2020

Take any complex number and measure its angle.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife

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