Instructional Video
Khan Academy

Khan Academy: Algebra: Complex Numbers: I as the Principal Root of 1

9th - 10th
Video shows the logic behind why some believe that saying i is the principal root of -1 is wrong. Explains why the logic is faulty. Explains more technically the meaning of principal root. [6:44]
Instructional Video
Khan Academy

Khan Academy: The Imaginary Unit I: I as the Principal Root of 1

9th - 10th
Video shows the logic behind why some believe that saying i is the principal root of -1 is wrong.
Instructional Video
Khan Academy

Khan Academy: Algebra: Complex Numbers: Imaginary Roots of Negative Numbers

9th - 10th Standards
Video shows how to simplify the square root of a negative number using the imaginary unit i. [4:04]
Instructional Video
Khan Academy

Khan Academy: The Imaginary Unit I: Imaginary Roots of Negative Numbers

9th - 10th Standards
Video shows how to simplify the square root of a negative number using the imaginary unit i.
Instructional Video
Sophia Learning

Sophia: Complex Numbers

9th - 10th Standards
Complex numbers are investigated in this video lesson. The tutorial demonstrates how to add, subtract, and multiply with the imaginary number i.
Instructional Video
Virtual Nerd

Virtual Nerd: How Do You Multiply Pure Imaginary Numbers?

9th - 10th Standards
This tutorial demonstrates the steps to find the product of pure imaginary numbers. [5:23]
Instructional Video
Khan Academy

Khan Academy: Algebra: Complex Numbers: Introduction to I and Imaginary Numbers

9th - 10th Standards
Video introduces i as the imaginary unit, gives two versions of the definition for i, and then shows what various powers of i equal. [5:20]
Instructional Video
Study Pug

Study Pug: Introduction to Imaginary Numbers

9th - 10th Standards
Video tutorial introduces the notion of imaginary numbers, and how to simplify them. [10:19]
Instructional Video
Study Pug

Study Pug: Complex Numbers and Complex Planes

9th - 10th Standards
Watch this video to learn what makes up a complex number, as well as how to plot on a complex plane. [5:45]
Instructional Video
Khan Academy

Khan Academy: Precalculus: Imaginary and Complex Numbers: Basic Complex Analysis

9th - 10th Standards
This Khan Academy video lesson provides a concrete way to help students represent and visualize complex numbers. An Argand Diagram, magnitude, modulus, argument, and exponential forms are utilized in the lesson.
Instructional Video
Sophia Learning

Sophia: Dividing Complex Numbers

9th - 10th Standards
This video lesson demonstrates how to divide with complex numbers, including the imaginary number i. The tutorial includes detailed examples. [3:26]