This shows grade level based on the word's complexity.

# complex number

Save This Word!

This shows grade level based on the word's complexity.

noun

a mathematical expression (a + bi) in which a and b are real numbers and i2 = −1.

QUIZ

CAN YOU ANSWER THESE COMMON GRAMMAR DEBATES?

There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?

Question 1 of 7

Which sentence is correct?

## Origin of complex number

First recorded in 1825–35

## Words nearby complex number

complexion, complexioned, complexionless, complexity, complexity theory, complex number, complexometric titration, complexometry, complexone, complex plane, complex salt

Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

## How to use complex number in a sentence

## British Dictionary definitions for complex number

complex number

noun

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

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

## Scientific definitions for complex number

complex number

[ kŏm′plĕks′ ]

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 + 5i.

The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.