Khan Academy
Khan Academy: Algebra: Complex Numbers: Introduction to I and Imaginary Numbers
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]
Khan Academy
Khan Academy: Adding Complex Numbers
Video describing how to add and subtract complex numbers with examples.
Khan Academy
Khan Academy: Precalculus: Imaginary and Complex Numbers: Basic Complex Analysis
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.
Sophia Learning
Sophia: Unreal Roots: Lesson 3
This lesson will demonstrate how to determine if a quadratic equation has unreal roots. It is 3 of 10 in the series titled "Unreal Roots."
Sophia Learning
Sophia: Unreal Roots: Lesson 1
This lesson will demonstrate how to determine if a quadratic equation has unreal roots. It is 1 of 10 in the series titled "Unreal Roots."
Sophia Learning
Sophia: Unreal Roots: Lesson 2
This lesson will demonstrate how to determine if a quadratic equation has unreal roots. It is 2 of 10 in the series titled "Unreal Roots."
Sophia Learning
Sophia: Quadratic Formula and Complex Numbers
Explains how complex numbers are related to the quadratic formula, in particular talks about the determinant of the quadratic formula being a negative.
Sophia Learning
Sophia: Quadratic Formula and Complex Numbers
Explains how complex numbers are related to the quadratic formula, in particular talks about the determinant of the quadratic formula being a negative.