
imaginary number


The complex number introduced to make it possible to solve equations without any real solution, such as x^{2} + 1 = 0.
A complex number takes the form z = x + yi, in which x and y are real numbers and i is called the imaginary unit with the property of i^{2} = 1. This imaginary unit can be considered to be the square root of minus one. x is the real part and yi is the imaginary part.

