Algebra of Complex Numbers

Overview


The algebra of the Complex Numbers is based on the definition of the complex numbers and the corresponding algebra of real numbers.

A generic complex number {% z %} is expressed as
{% z = x+iy %}

Algebraic Definitions


Given two complex numbers, {% z_1 = x_1 + iy_1 %} and {% z_2 = x_2 + iy_2 %}, the following operations are defined:

  • Addition
    {% z_1 + z_2 = (x_1 + x_2) + i(y_1 + y_2) %}
  • Multiplication
    {% z_1 \times z_2 = (x_1 x_2 - y_1 y_2) + i(y_1 x_2 + x_1 y_2) %}

Representing Complex Numbers as Vectors


Complex numbers can be represented as an ordered pair
{% z = (x,y) %}
with the corresponding algebraic Properties
{% z_1 + z_2 = (x_1 + x_2,y_1 + y_2) %}
{% z_1 \times z_2 = (x_1 x_2 - y_1 y_2, y_1 x_2 + x_1 y_2) %}

Implementation


The implementation of compex numbers will typically rely on the vector representation as given above. The complex numbers api represents a complex number as an array of two numbers.

For example, the number {% 1 + 2i %} is represented as


let z = [1,2];