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Learn about the imaginary unit, "i", a unique number defined as the square root of -1. It's a key part of complex numbers, which are in the form a + bi. The powers of "i" cycle through a set of values.

Imaginary numbers - Introduction

Introduction to Imaginary Numbers

Imaginary Numbers 3 - Powers of i (lesson video) by Mathematics Made Easy

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Simplifying Complex Numbers

Intro to the imaginary numbers (video)

An easy, alternative introduction to Imaginary Numbers

Intro to the imaginary numbers (video)

What are the 5th roots of 5-i? - Quora

Factoring polynomials using complex numbers (video)