imaginary part

American

noun

Mathematics.

the coefficient b in the complex number a + bi.

imaginary part British

noun

the coefficient b in a complex number a + i b , where i = √–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

Etymology

Origin of imaginary part

First recorded in 1925–30

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.

Phoenix was imaginary, part of a 2009 government preparation exercise for a killer hurricane dubbed Project Phoenix — an exercise updated in 2020 focusing on small business recovery.

From Seattle Times • Sep. 27, 2022

We call a the real part and b the imaginary part.

From Textbooks • May 6, 2020

This term is called the complex conjugate of the denominator, which is found by changing the sign of the imaginary part of the complex number.

From Textbooks • Feb. 13, 2015

Yet let’s remember that z can be any complex number, formed from a real part and an imaginary part: x+iy.

From Scientific American • Sep. 26, 2012

The horizontal axis represents the real part of the complex number, while the vertical axis represents the imaginary part.

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

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