University of Toronto (Canada)
Do "Imaginary Numbers" Really Exist?
Contains a brief explanation of the existence of imaginary numbers.
Wolfram Research
Wolfram Math World: Real Axis
This MathWorld site contains a definition and graphical example of the real axis in a complex plane.
Wolfram Research
Wolfram Math World: Imaginary Axis
Contains a graphical example of the imaginary axis in a complex plane.
Math Words
Math words.com: Complex Numbers
At MathWords.com, a definition is given for what complex numbers are, along with some examples.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Numeros Complejos
Practice how to represent complex numbers graphically, operations with complex numbers and geometric transformations.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Complejos
In this unit you can practice interactively the concept of complex numbers in binomial and polar forms.
Other
Imaginary Numbers Are Not Imaginary.
This site explores the concept of why imaginary numbers are not imaginary.
Other
University of Delaware: Complex Numbers
Contains a brief summary of complex numbers related with vectors.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Complex Numbers
Find a quick, concise explanation of Complex Numbers.
Interactive Mathematics
Interactive Mathematics: Complex Numbers
The world of complex numbers is explored through mini lessons, interactive examples, applications and demonstrations. Topics covered include definitions, basic operations, graphing, different forms of complex numbers, products,...
Interactive Mathematics
Interactive Mathematics: Exponential Form of a Complex Number
Several examples are presented to demonstrate how to write complex numbers in exponential for. The demonstrations concludes with a comparison of different forms complex numbers: rectangular, exponential, and polar.
That Quiz
That Quiz: Puntos
This is an interactive practice test to review graphing points on the Cartesian, Polar and Complex plane. Test are timed and keep track of right and wrong answers.
Windstream
Ojk's Precalculus Study Page: Polar Coordinates and Complex Numbers
An introduction to basic conversion formulas for polar coordinates and complex numbers. Includes several examples.
Johan Claeys
Polar Form of Complex Numbers
Contains a brief explanation of polar forms of complex numbers.
University of Toronto (Canada)
The Origin of Complex Numbers and the Notation "I"
Contains a brief summary on the origin of complex numbers.
National Council of Teachers of Mathematics
The Math Forum: Drexel University Math Forum: Imaginary Numbers
Contains a short summary on imaginary numbers and several links to its related fields. Also provides several examples and explanations for understanding.
Other
Gobierno De Navarra: Numeros Complejos
Use these interactive activities as a supplementary material to practice sum, difference, multiplication and division, power and roots of complex numbers.
Interactive Mathematics
Interactive Mathematics: Graphical Representation of Complex Numbers
A description of the complex plane is given with examples of how to plot complex numbers. Also included is an explanation of how to add complex numbers graphically.
Friesian School
Friesian.com: Imaginary Numbers
This site from Friesian.com contains a detailed definition of imaginary numbers along with a few examples.
Interactive Mathematics
Interactive Mathematics: De Moivre's Theorem
Using DeMoivre's Theorem, the powers and roots of complex numbers are simplified. Several examples are given, including interactive exercises.
Math Words
Math words.com: Complex Plane
Contains the definition and a picture for what a complex plane is.