ABSTRACT
Complex Numbers ◮ Definition of a complex number. Geometric interpretation. The set of complex numbers is an extension of the set of real numbers. An expression of the form z = x + iy, where x and y are real numbers, is called a complex number, and the symbol i is called the imaginary unit, which possesses the property i2 = –1. The numbers x and y are called, respectively, the real and imaginary parts of z and denoted by
x = Re z and y = Im z.
