**en.wikipedia.org**/wiki/**Imaginary_number**

An imaginary number is a complex number that can be written as a real number multiplied by the imaginary unit i, which is defined by its property i 2 = −1. The square of an imaginary number bi is −b 2. For example, 5i is an imaginary number, and its square is −25. Zero is considered to be both real and imaginary.

rossroessler.tripod.com

Issac Newton agreed with Descartes, and Albert Girad even went as far as to call these, “solutions impossible”. Although these people didn’t enjoy the thought of imaginary numbers, they couldn’t stop other mathematicians from believing that i might exist.

mathforum.org/library/drmath/view/52584.html

History of Imaginary Numbers Date: 03/09/2001 at 13:57:56 From: Laurie Raley Subject: Who Invented Imaginary Numbers? Hello, I am a high school student Chicago, IL, and my class just started studying imaginary numbers. ... , "The terms IMAGINARY and REAL were introduced in French by Rene Descartes (1596-1650) in "La Geometrie" (1637 ...

math.stackexchange.com/questions/845854/**descartes-on-imaginary-unit**

I heard once that Descartes defining the imaginary unit had to talk about the imagining of rise of the spirit over the real numbers because definition based on square root of a negative number could end up for him with ostracism from the scientific community.

www.theproblemsite.com/.../algebra/complex-**numbers**/**introduction-imaginary-numbers**

If you feel that way, you're in good company with some historical mathematicians like Rene DesCartes, who didn't think there was much point to these strange numbers. However, despite the fact that they are called imaginary, there are actually some real-world applications for these numbers.

**scienceblogs.com**/goodmath/2008/12/25/i-the-**imaginary**-**number**-classic

It got its unfortunate misnomer, the "imaginary number" as a result of a diatribe by Rene Descartes. Descartes was disgusted by it; he believed it was a phony artifact of sloppy algebra. ...

friesian.com/imagine.htm

That there actually are no imaginary numbers now does not mean that they are nothing: They exist conceptually, or intentionally, in representation, which is as much reality as they need before some operation produces real numbers and real results. Imaginary numbers are indeed imaginary.

**en.wikipedia.org**/wiki/**René_Descartes**

René Descartes was born in La Haye en Touraine (now Descartes, Indre-et-Loire), France, on 31 March 1596. His mother, Jeanne Brochard, died soon after giving birth to him, and so he was not expected to survive. Descartes' father, Joachim, was a member of the Parlement of Brittany at Rennes. René lived with his grandmother and with his great-uncle.

www.ukessays.com/essays/mathematics/**imaginary-and-complex-numbers**.php

Soon after Rene Descartes’ contributions, the mathematician John Wallis produced a method for graphing complex numbers on a number plane. For real numbers, a horizontal number line is used, with numbers increasing in value as you move to the left. John Wallis added a vertical line to represent the imaginary numbers.

**plato.stanford.edu**/entries/**descartes-mathematics**

Descartes, René, 1637, The Geometry of Rene Descartes with a facsimilie of the first edition, translated by David E. Smith and Marcia L. Latham. New York: Dover Publications, Inc., 1954. [cited as G followed by page number] –––, 1985, The philosophical writings of Descartes. Two volumes, translated by John Cottingham, Robert Stoothoff ...