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. Originally coined in the 17th century by René Descartes as a derogatory term ...

www.quora.com/Who-discovered-imaginary-numbers

The first use or effort of using imaginary number [1] dates back to [math]50[/math] AD. Heron of Alexandria [2] , while studying the volume of an impossible pyramid came upon an expression [math]\sqrt{81–114}[/math]. However, he deemed it was impo...

www.mathsisfun.com/numbers/imaginary-numbers.html

Imaginary Numbers are not "Imaginary". Imaginary Numbers were once thought to be impossible, and so they were called "Imaginary" (to make fun of them).. But then people researched them more and discovered they were actually useful and important because they filled a gap in mathematics ... but the "imaginary" name has stuck.. And that is also how the name "Real Nu...

www.math.uri.edu/~merino/spring06/mth562/ShortHistoryComplexNumbers2006.pdf

A fact that is surprising to many (at least to me!) is that complex numbers arose from the need to solve cubic equations, and not (as it is commonly believed) quadratic equations. These notes track the development of complex numbers in history, and give evidence that supports the above statement. 1.

www.123helpme.com/essay/The-History-of-Imaginary-Numbers-125457

So, from the new found knowledge of negative numbers mathematicians discovered imaginary numbers. Around 1545 Girolamo Cardano, an Italian mathematician, solved what seemed to be an impossible cubic equation.

rossroessler.tripod.com

History of Complex Numbers (also known as History of Imaginary Numbers or the History of i) For school, I had to do a paper on the History of i (and the history of complex numbers in general). Finding this a tedious task, and scrolling through many useless sights, I wished that there were just one sight that had everything I needed on it.

www.sciencefocus.com/science/a-brief-introduction-to-imaginary-numbers

For instance, 4 + 2i is a complex number with a real part equal to 4 and an imaginary part equal to 2i. It turns out that both real numbers and imaginary numbers are also complex numbers. For example, 17 is a complex number with a real part equal to 17 and an imaginary part equalling zero, and iis a complex number with a real part of zero.

www.scienceabc.com/nature/what-are-imaginary-numbers-why-are-they-so-important...

Imaginary numbers? As if the numbers we already have weren’t enough. The commentary on mathematics’ difficulty has become a platitude. We’re all aware that some proportion of all high schoolers are terrified by the unintelligible language their math textbooks are scribbled with, like Victorian readers encountering Ulysses for the very first time.

sciencing.com/what-are-imaginary-numbers-13712190.html

In the late 1500s, mathematicians discovered the existence of imaginary numbers. Imaginary numbers are needed to solve equations such as x^2 + 1 = 0. To distinguish imaginary numbers from real ones, mathematicians use the letter i, usually in italics, such as i, 3i, 8.4i, where i is the square root of -1 and the number before it serves as a ...

www.answers.com/Q/How_were_imaginary_numbers_discovered

Imaginary numbers were discovered when mathematicians tried to solve equations of the form x^2 + 2 = 0