CK-12 Foundation
Ck 12: Imaginary Numbers
[Free Registration/Login may be required to access all resource tools.] Know there is a complex number i such that i squared = -1, and every complex number has the form a + bi with a and b real.
CK-12 Foundation
Ck 12: Quadratic Formula and Complex Sums
[Free Registration/Login may be required to access all resource tools.] Represent complex numbers on the complex plane in rectangular and polar form (including real and imaginary numbers), and explain why the rectangular and polar forms...
CK-12 Foundation
Ck 12: Polar Form of Complex Numbers
[Free Registration/Login may be required to access all resource tools.] Represent addition, subtraction, multiplication, and conjugation of complex numbers geometrically on the complex plane; use properties of this representation for...
Larson Texts
Larson Precalculus: Operations of Complex Numbers in the Complex Plane [Pdf]
A 3-page handout with examples and exercises in adding, subtracting, and multiplying complex numbers in the complex plane, as well as finding complex conjugates.
Other
Mrao: Imaginary Numbers Are Not Real
This site presents a tutorial introduction to the ideas of geometric algebra. Gives an outline of geometric algebra and discusses the geometric product, imaginary numbers, and more.
Math Planet
Math Planet: Algebra 2: Complex Numbers
Provides an explanation, examples, and a video lesson all related to complex numbers.
Mathigon
Mathigon: Real, Irrational, Imaginary Numbers
Explore this course in imaginary and complex numbers including topics of integers, real numbers, infinity, transcendental numbers, imaginary and complex numbers.
Math Warehouse
Math Warehouse: Complex and Imaginary Numbers
Features numerous exercises relating to complex and imaginary numbers. Includes video tutorials, calculators, worksheets and more.
Cool Math
Coolmath: Factoring Complex Numbers Exercises
This Algebra Cruncher generates an endless number of practice problems for factoring the sum of two squares. Each problem has hints and solutions.
Illustrative Mathematics
Illustrative Mathematics: N cn.a.2: Powers of a Complex Number
The goal of this task is to practice making calculations with complex numbers and to visualize what happens when two complex numbers are multiplied. Aligns with N-CN.A.2.
Illustrative Mathematics
Illustrative Mathematics: N Cn, a Rei Complex Square Roots
Working with complex numbers allows us to solve equations that cannot be solved with real numbers. Here we will investigate complex numbers which arise as square roots of certain complex numbers. Aligns with N-CN.A.2 and A-REI.A.1.
Khan Academy
Khan Academy: Graphically Add and Subtract Complex Numbers
Add or subtract complex numbers, and plot the result in the complex plane. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Multiply Complex Numbers
Given two complex numbers, find their product. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Multiply Complex Numbers (Basic)
Multiply complex numbers by single terms that are either real or imaginary. Students receive immediate feedback and have the opportunity to try questions repeatedly or receive hints.
Khan Academy
Khan Academy: Divide Complex Numbers
Given a complex number division problem, express the result as a complex number of the form a+bi. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Complex Number Conjugates
Given a complex number, find its conjugate or plot it in the complex plane. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Angle of Complex Numbers
Given a complex number of the form a+bi, find its angle. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Lawrence Hall of Science
The Math Page: Skill in Algebra: Skill in Algebra: Complex or Imaginary Numbers
Clearly and thoroughly explains complex numbers. Provides example problems and exercises for students, with solutions available.
CK-12 Foundation
Ck 12: Analysis: Products and Quotients of Complex Numbers
[Free Registration/Login may be required to access all resource tools.] In this lesson, students calculate the products and quotients of complex numbers, identifying conjugates. Students examine guided notes, review guided practice,...
CK-12 Foundation
Ck 12: Polar Form of a Complex Number
[Free Registration/Login may be required to access all resource tools.] Here you will learn how to convert complex numbers from rectangular form to polar form. You will also explore the graphs of complex numbers on a polar graph.
CK-12 Foundation
Ck 12: Complex Numbers
[Free Registration/Login may be required to access all resource tools.] This lesson covers the powers of i, and adding and subtracting complex numbers, as well as how to plot them in the complex plane. Students examine guided notes,...
CK-12 Foundation
Ck 12: Products and Quotients of Complex Numbers
[Free Registration/Login may be required to access all resource tools.] A collection of resources for learning about and practicing how to multiply and divide complex numbers.
CK-12 Foundation
Ck 12: Complex Numbers
[Free Registration/Login may be required to access all resource tools.] A collection of resources that explain complex numbers and how to do arithmetic with them.