Dividing two complex numbers involves dividing their moduli and subtracting their arguments. An animation (using GeoGebra) is used to illustrate these ideas.
Detailed solutions of the following examples are given:
1. Use polar forms to show that i/-i = -1
2. For z=1 and w=1-i use polar forms to evaluate z/w.
3. Let z=-1+√3i and w=-√3-i
(a) Give the polar forms of z and w.
(b) Use your part (a) answer to evaluate z/w.
(c) Obtain your part (b) answer without using polar forms.
The viewer is encouraged to attempt these questions before watching the solutions.
Chapters:
00:00 Introductory animation
04:52 Mathematical derivation of results
08:55 The examples
09:09 Solution to Example 1
11:55 Solution to Example 2
15:11 Solution to Example 3
23:58 Links to the Playlist "Complex Numbers"
Previous videos in this series are:
01 What is a Complex Number?
02 Adding, Subtracting and Multiplying Complex Numbers
03 Dividing Complex Numbers
04 Complex Conjugates
05 The Field of Complex Numbers
06 The Complex Plane
07 The Modulus of a Complex Number
08 Distance on the Complex Plane
09 Properties of the Modulus of a Complex Number
10 Complex Numbers and the Unit Circle
11 The Polar Form of a Complex Number
12 The Principal Argument of a Complex Number
13 The Geometrical Effects of Multiplying by a Complex Number
14 Multiplication of Complex Numbers in Polar Form
15 The Principal Argument when Multiplying Complex Numbers
16 The Geometrical Effects of Dividing by a Complex Number
Key words: Complex division, modulus, argument, difference, subtraction, division, conjugate, principal value, Arg(z), polar form, cartesian form.
M337, Open University, Unit A1, complex analysis