Introduction to complex numbers, their properties, and operations explained in an easy-to-understand manner. Learn about real and imaginary parts, addition, subtraction, multiplication, …

Sal explains how we obtain complex numbers by adding real numbers and imaginary numbers. Created by Sal Khan.

Review the polar form of complex numbers, and use it to multiply, divide, and find powers of complex numbers.

How do we divide complex numbers? Dividing a complex number by a real number is simple. For example:

Algebra of Complex Numbers Learn Adding complex numbers Subtracting complex numbers Multiplying complex numbers

Discover how to multiply complex numbers! Just like multiplying regular numbers, you can use the distributive property or FOIL method. Remember, the imaginary unit 'i' squared equals -1. So, …

VA.Math: A2.EO.4.c VA.Math.2023: A2.EO.4.c Google Classroom Microsoft Teams Multiply and simplify the following complex numbers: (2 4 i) ⋅ (1 i)

Sometimes, thinking of i as a variable, like x , is helpful. Then, with just a few adjustments at the end, we can multiply just as we'd expect. Let's take a closer look at this by walking through …

We can multiply complex numbers graphically on the complex plane by rotating and scaling. Multiplying a complex number z by -3i rotates and scales z.

The table below shows examples of complex numbers, with the real and imaginary parts identified. Some people find it easier to identify the real and imaginary parts if the number is …