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# Complex numbers

10 videos
6 skills
Let's start constructing numbers that have both a real and imaginary part. We'll call them complex. We can even plot them on the complex plane and use them to find the roots of ANY quadratic equation. The fun must not stop!

### Introduction to complex numbers

VIDEO 4:39 minutes

### The imaginary unit and complex numbers

PRACTICE PROBLEMS

### Plotting complex numbers on the complex plane

VIDEO 1:14 minutes

### The complex plane

PRACTICE PROBLEMS
Plot complex numbers on the complex plane.

### Adding complex numbers

VIDEO 1:11 minutes
Adding Complex Numbers

### Subtracting complex numbers

VIDEO 1:53 minutes
Subtracting Complex Numbers

### Adding and subtracting complex numbers

PRACTICE PROBLEMS

### Multiplying complex numbers

VIDEO 5:32 minutes
Multiplying Complex Numbers

### Multiplying complex numbers

PRACTICE PROBLEMS

### Complex conjugates example

VIDEO 4:01 minutes
Complex Conjugates

### Dividing complex numbers

VIDEO 4:58 minutes
Dividing Complex Numbers

### Dividing complex numbers

PRACTICE PROBLEMS

### Absolute value of a complex number

VIDEO 3:33 minutes

### Absolute value of complex numbers

PRACTICE PROBLEMS
Find the absolute value of a complex number.

### Example: Complex roots for a quadratic

VIDEO 10:15 minutes
Complex Roots from the Quadratic Formula

### Algebra II: Imaginary and complex numbers

VIDEO 9:55 minutes
21-26, mostly imaginary and complex numbers