Complex Numbers

How Do You Multiply Complex Numbers Using FOIL?

Get some practice multiplying complex numbers together using the FOIL method! This tutorial takes you through the process of multiplying two complex numbers together.
How Do You Add Complex Numbers?

If you want to add complex numbers together, first regroup them so that like terms are next to one another. Then, add the like terms together, and you have your answer! To see an example, check out this tutorial.
How Do You Subtract Complex Numbers?

When you subtract complex numbers, you first need to distribute in the minus sign into the second complex number. Then, regroup the terms so like terms are next to each other. Combine those like terms, and you have the answer! Watch this tutorial to see a great example!
How Do You Divide Complex Numbers Using Conjugates?

To divide complex numbers, you usually need to multiply by the complex conjugate of the denominator. Follow along with this tutorial to see how to find that complex conjugate and multiply with it to perform the division!
What is the Imaginary Unit i?

Every tried to take the square root of a negative number? You'll need the imaginary unit 'i' to write the answer. This tutorial introduces you to this useful imaginary unit.
What is an Imaginary Number?

Imaginary numbers are used to help us work with numbers that involve taking the square root of a negative number. In this tutorial, you'll be introduced to imaginary numbers and learn that they're a type of complex number.