Instructional Video
Khan Academy

Khan Academy: Pre Calculus: Exponential Form to Find Complex Roots

9th - 10th Standards
This video illustrates how the exponential form of a complex number can be helpful in finding the complex roots of a number. The process is shown both algebraically and graphically using x^3 = 1 as a simple example. [11:53]
Instructional Video
Khan Academy

Khan Academy: Algebra: Multiplying Binomials With Radicals

9th - 10th Standards
Video demonstrates how to multiply two polynomials when each polynomial contains one variable term and one radical (constant) term. [6:03]
Instructional Video
Khan Academy

Khan Academy: Algebra: Complex Numbers: Complex Roots From the Quadratic Formula

9th - 10th Standards
Video shows how to use the quadratic formula to find roots of a quadratic equation in a situation where the roots are complex. Includes showing how to verify the answers are correct solutions of the quadratic. [10:15]
Instructional Video
Khan Academy

Khan Academy: Complex Roots of the Characteristic Equations 2

9th - 10th Standards
What happens when the characteristic equation has complex roots?
Instructional Video
Khan Academy

Khan Academy: Repeated Roots of the Characteristic Equation

9th - 10th Standards
What happens when the characteristic equation only has 1 repeated root?
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
Sophia Learning

Sophia: Decartes' Rule of Signs

9th - 10th Standards
Determine the number of real roots of a given polynomial function using Decartes' rule of signs. Assess learning with a quiz.
Instructional Video
Khan Academy

Khan Academy: Complex Roots of the Characteristic Equations 3

9th - 10th Standards
Complex and repeated roots of characteristic equation.
Instructional Video
Khan Academy

Khan Academy: Polynomial Basics: Adding and Subtracting Polynomials 1

9th - 10th Standards
This video demonstrates how to add trinomials.
Instructional Video
Khan Academy

Khan Academy: Algebra: Complex Conjugates Example

9th - 10th Standards
Video shows how to write the conjugate of a complex number. Also discusses uses of the complex conjugate and shows an example of multiplying complex conjugates. [4:01]
Instructional Video
Khan Academy

Khan Academy: Quadratic Odds and Ends: Introduction to the Quadratic Equation

9th - 10th Standards
The video demonstrates how to use the quadratic equation to solve second degree polynomials.
Instructional Video
Khan Academy

Khan Academy: Algebra: Factoring Sum of Cubes

9th - 10th Standards
Video demonstrates how to recognize and factor a sum of cubes. [4:46]
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: Finding a Polynomial Passing Through a Point: Lesson 3

9th - 10th Standards
This lesson uses the linear factorization theorem to find a particular function polynomial passing through a point given the zeros of that function. It is 3 of 7 in the series titled "Finding A Polynomial Passing Through A Point."
Instructional Video
Shmoop University

Shmoop: Factoring Polynomials

9th - 10th Standards
Short video explaining factoring polynomials.