INDEX
Numbers and Sets
Exponentiation
Algebraic Transformations
Algebraic Equations and Inequalities
Functions
Discrete Algebra
Basic Formulas
Graphics of Basic Functions
Complex Numbers
Ship 2

Definition and Properties

Basic Definitions

Algebraic Operations

Complex Conjugation

Trigonometrical and Exponential Forms

The Complex Plane

Complex Numbers in Polar Coordinate System

The Euler Formula
  Trigonometric Applications
  Algebraic Applications

Powers of Complex Numbers

Complex Roots


Complex Roots

In view of periodicity of trigonometric functions sine and cosine, a complex number can be rewritten in the polar form as follows:

.

The  nth roots of  z are determined by expression

.

By substituting  m = 0, 1, 2, 3, ...  we obtain all roots  tm  of a complex number. There exist  n  different roots exactly:

The next value of integer  m  gives the root  tn+1  that coincides with  t1:

Note that all roots have the same modulus  , that is, they lie on the circle with the radius  .

There is a simple way to plot all  n  roots of a number  z  when one of the roots is known. We need only to divide the circle with radius    into  n equal parts, starting from the point on the circle that corresponds to a root of  z.


Examples
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