https://en.wikipedia.org/wiki/Complex_number

A complex number is a number that can be expressed in the form a + bi, where a and b are real ..... The rules for addition, subtraction, multiplication, and root extraction of complex numbers were developed by the Italian ... The term " imaginary" for these quantities was coined by René Descartes in 1637, although he was at ...

https://en.wikipedia.org/wiki/Imaginary_number

An imaginary number is a complex number that can be written as a real number multiplied by ... Originally coined in the 17th century as a derogatory term and regarded as fictitious or useless, the concept ... At the time imaginary numbers, as well as negative numbers, were poorly understood and regarded by some as ...

http://rossroessler.tripod.com/

For a very long time, no one tried to manipulate imaginary numbers. Although, it wasn't for a lack of trying. Once negative numbers were “invented”, ...

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

notes track the development of complex numbers in history, and give evidence that supports the ... The methods of algebra known to the arabs were introduced in Italy by the Latin transla- tion of the .... Descartes coined the term imaginary:.

https://www.quora.com/Why-were-complex-numbers-invented-Were-they-invented-to-explain-a-physical-phenomenon-or-do-they-really-exist

If you start working with certain concepts over the real numbers, you'll notice various rather bizarre dichotomies. For instance, you can ...

https://www.math.toronto.edu/mathnet/questionCorner/complexorigin.html

Oct 29, 1996 ... Complex numbers were being used by mathematicians long before they ... interpretation of complex numbers as points in a plane, which made ...

If they are confronted with the equation x+3=0, they find that their number system is inadequate. So they invent negative numbers and so ...

https://www.storyofmathematics.com/19th_gauss.html

There are many anecdotes concerning his precocity as a child, and he made his first ... Gauss gave the first clear exposition of complex numbers and of the investigation ... Gauss' achievements were not limited to pure mathematics, however.

http://www.math.utep.edu/Faculty/tuesdayj/math1508/1508Ch2Sec4.pdf

This is how complex numbers were “invented.” A simple quadratic ... A guy named Cardano developed complex numbers off the base of the imaginary number.