# Ch 16: Compass Math: Complex Numbers

### About This Chapter

## Compass Math: Complex Numbers - Chapter Summary

Study for the Compass Math exam as you prepare to enter college. The lessons in this chapter examine complex number problems. Lesson topics include:

- Defining imaginary numbers
- Adding and subtracting complex numbers
- Multiplying and dividing complex numbers
- Graphing complex numbers on a complex plane

Our experienced instructors provide informative video lessons taught in an easygoing manner as well as engaging visuals to make studying fun. The lessons are convenient. Each one is less than 10 minutes long and can be watched on your smartphone or tablet. You can watch them as often as necessary to fully grasp the materials or you can use video tags to jump to portions of the lesson you want to see again.

### Compass Math: Complex Numbers Chapter Objectives

The ACT Compass Math test is used by post-secondary institutions to place incoming students into the appropriate math classes. The test is computerized and all questions are multiple choice. No time limit is placed upon students to finish the test, so you can answer questions at your own pace.

Questions on complex numbers are asked on the college algebra portion of the ACT Compass Math test. Use our multiple-choice quizzes and chapter exam to practice answering these types of questions on the test.

### 1. What is an Imaginary Number?

The imaginary number 'i' is the square root of -1. Although this number doesn't actually exist, pretending that it does allows us to do a bunch of crazy math that scientists use every day. Learn the basics of that number 'i' here!

### 2. How to Add, Subtract and Multiply Complex Numbers

Knowing that complex numbers exist is the first step. But that knowledge alone won't help you do much with them. Learn the basics of complex number addition, subtraction and multiplication here!

### 3. How to Divide Complex Numbers

While adding, subtracting and multiplying complex numbers is pretty straightforward, dividing them can be pretty tricky. It comes down to the process of multiplying by the complex conjugate. Learn about what that is, and how to do it, here.

### 4. How to Graph a Complex Number on the Complex Plane

Graphing complex numbers is pretty straight forward, but it's not necessarily intuitive. Check out this lesson to learn the vocabulary and the conventions that you'll need.

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### Other Chapters

Other chapters within the ACT Compass Math Test: Practice & Study Guide course

- Compass Math: Integers
- Compass Math: Decimals
- Compass Math: Fractions
- Compass Math: Exponents
- Compass Math: Roots & Radicals
- Compass Math: Percents
- Compass Math: Ratios, Rates & Proportions
- Compass Math: Median, Mean & Mode
- Compass Math: Algebraic Equations & Expressions
- Compass Math: Linear Equations
- Compass Math: Substituting Values
- Compass Math: Monomials & Polynomials
- Compass Math: Factoring Polynomials
- Compass Math: Matrices & Absolute Value
- Compass Math: Inequalities
- Compass Math: Logarithms
- Compass Math: Basic Geometry
- Compass Math: Lines & Angles
- Compass Math: Polygons
- Compass Math: Triangles
- Compass Math: Quadrilaterals
- Compass Math: Circles
- Compass Math: Similar Figures
- Compass Math: Complex Figures
- Compass Math: Constructions
- Compass Math: Area, Circumference & Perimeter
- Compass Math: Mathematical Modeling
- Compass Math: Quadratics
- Compass Math: Quadratic Functions
- Compass Math: Trigonometric Functions
- Compass Math: Rational Functions
- Compass Math: Function Operations
- Compass Math: Trigonometric Identities
- Compass Math: Trigonometric Equations
- Compass Math: Trigonometric Applications
- Compass Math: Trigonometric Graphs
- Compass Math: Graph Symmetry
- Compass Math: Polar Coordinates & Parameterization