Trigonometry Online Course


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Workbook $37.49 View details
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Thinkwell's Trigonometry with Professor Edward Burger

Thinkwell's Trigonometry homeschool course has engaging online video lessons and step-by-step exercises that teach you what you'll need to be successful in Calculus. The Trigonometry curriculum covers trig functions, identities, ratios and more.  Instead of trying to learn what you need from an old-fashioned textbook, you can watch easy-to-understand trigonometry videos.

Thinkwell's award-winning math teacher, Edward Burger, can explain and demonstrate trig clearly to anyone, so trigonometry basics are easy to understand and remember. Professor Burger shares the tricks and tips so your students will remember them when they begin calculus.

The workbook (optional) comes with lecture notes, sample problems, and exercises so that you can study even when away from the computer.

Course Features

Video Lessons

195 engaging 5-10 minute lesson videos
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Lesson Plan

Detailed, 36-week lesson plan and schedule
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Automatically graded exercises and tests
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Notes & Sample Problems

Illustrated course notes, sample problems & solutions
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What Parents Are Saying. . .
"My son used Thinkwell intermediate algebra, college algebra, trigonometry, and is now using Professor Burger's Calculus course. I can't say enough about how much he learns from this method of learning, and how much he likes it! He likes it so much that his younger sibling asked me to buy 8th grade math for her. Prof Burger makes total sense and explains very clearly. He's funny, too. I know some people, those of a serious bent, can be taken aback by his style (silly at times, or just nerdy-silly), but he grows on you until you enjoy him so much, and his humor is part of what makes you learn so well. After all, a happy, relaxed brain is going to receive information better than a stressed brain!"
– MG
"We love Thinkwell. If we could take all our classes from them, we would. My kids talk about the pre-recorded lectures as "My professor said" and "my professor does" just as though they had real face-to-face contact with the instructors every day. We can't wait for next year. We're already planning to take two math and one science class through Thinkwell next year. I tell everyone about Thinkwell!”
– Lessa S
Course Overview

what you get

  • 12-month, online subscription to our complete Trigonometry course
  • 36-week, day-by-day
  • 190+ course lessons, each with a streaming video
  • Automatically graded drill-and-practice exercises with step-by-step answer feedback
  • Sample problems and solutions
  • Chapter & Practice tests, a Midterm & Final Exam
  • Animated interactivities....and more!

How It Works

  • Purchase Thinkwell's Trigonometry through our online store
  • Create an account username and password which will give you access to the online Trigonometry course section
  • Activate your 12-month subscription when you're ready
  • Login to the course website to access the online course materials, including streaming video lessons, exercises, quizzes, tests and more
  • Access your course anytime, anywhere, from any device
  • Your work is automatically tracked and updated in real-time
  • Grade reports and certificates of completion are available at request
About Thinkwell's Trigonometry Author, Edward Burger

Learn from award-winning mathematician and Dr. Edward Burger

It's like having a world-class college professor right by your side teaching you Trigonometry.

  • "Global Hero in Education" by Microsoft Corporation
  • "America's Best Math Teacher" by Reader's Digest
  • Robert Foster Cherry Award Winner for Great Teaching
Thinkwell's Trigonometry Table of Contents
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1. Algebraic Prerequisites

1.1 Graphing Basics
1.1.1 Using the Cartesian System
1.1.2 Thinking Visually
1.2 Relationships between Two Points
1.2.1 Finding the Distance between Two Points
1.2.2 Finding the Second Endpoint of a Segment
1.3 Relationships among Three Points
1.3.1 Collinearity and Distance
1.3.2 Triangles
1.4 Circles
1.4.1 Finding the Center-Radius Form of the Equation of a Circle
1.4.2 Decoding the Circle Formula
1.4.3 Finding the Center and Radius of a Circle
1.4.4 Solving Word Problems Involving Circles
1.5 Graphing Equations
1.5.1 Graphing Equations by Locating Points
1.5.2 Finding the x- and y-Intercepts of an Equation
1.6 Function Basics
1.6.1 Functions and the Vertical Line Test
1.6.2 Identifying Functions
1.6.3 Function Notation and Finding Function Values
1.7 Working with Functions
1.7.1 Determining Intervals Over Which a Function Is Increasing
1.7.2 Evaluating Piecewise-Defined Functions for Given Values
1.7.3 Solving Word Problems Involving Functions
1.8 Function Domain and Range
1.8.1 Finding the Domain and Range of a Function
1.8.2 Domain and Range: One Explicit Example
1.8.3 Satisfying the Domain of a Function
1.9 Linear Functions: Slope
1.9.1 An Introduction to Slope
1.9.2 Finding the Slope of a Line Given Two Points
1.9.3 Interpreting Slope from a Graph
1.9.4 Graphing a Line Using Point and Slope
1.10 Equations of a Line
1.10.1 Writing an Equation in Slope-Intercept Form
1.10.2 Writing an Equation Given Two Points
1.10.3 Writing an Equation in Point-Slope Form
1.10.4 Matching a Slope-Intercept Equation with Its Graph
1.10.5 Slope for Parallel and Perpendicular Lines
1.11 Graphing Functions
1.11.1 Graphing Some Important Functions
1.11.2 Graphing Piecewise-Defined Functions
1.11.3 Matching Equations with Their Graphs
1.12 Manipulating Graphs: Shifts and Stretches
1.12.1 Shifting Curves along Axes
1.12.2 Shifting or Translating Curves along Axes
1.12.3 Stretching a Graph
1.12.4 Graphing Quadratics Using Patterns
1.13 Manipulating Graphs: Symmetry and Reflections
1.13.1 Determining Symmetry
1.13.2 Reflections
1.13.3 Reflecting Specific Functions
1.14 Quadratic Functions: Basics
1.14.1 Deconstructing the Graph of a Quadratic Function
1.14.2 Nice-Looking Parabolas
1.14.3 Using Discriminants to Graph Parabolas
1.14.4 Maximum Height in the Real World
1.15 Quadratic Functions: The Vertex
1.15.1 Finding the Vertex by Completing the Square
1.15.2 Using the Vertex to Write the Quadratic Equation
1.15.3 Finding the Maximum or Minimum of a Quadratic
1.15.4 Graphing Parabolas
1.16 Composite Functions
1.16.1 Using Operations on Functions
1.16.2 Composite Functions
1.16.3 Components of Composite Functions
1.16.4 Finding Functions That Form a Given Composite
1.16.5 Finding the Difference Quotient of a Function
1.16.6 Calculating the Average Rate of Change
1.17 Rational Functions
1.17.1 Understanding Rational Functions
1.17.2 Basic Rational Functions
1.18 Graphing Rational Functions
1.18.1 Vertical Asymptotes
1.18.2 Horizontal Asymptotes
1.18.3 Graphing Rational Functions
1.18.4 Graphing Rational Functions: More Examples
1.18.5 Oblique Asymptotes
1.18.6 Oblique Asymptotes: Another Example
1.19 Function Inverses
1.19.1 Understanding Inverse Functions
1.19.2 The Horizontal Line Test
1.19.3 Are Two Functions Inverses of Each Other?
1.19.4 Graphing the Inverse
1.20 Finding Function Inverses
1.20.1 Finding the Inverse of a Function
1.20.2 Finding the Inverse of a Function with Higher Powers

2. The Trigonometric Functions

2.1 Angles and Radian Measure
2.1.1 Finding the Quadrant in Which an Angle Lies
2.1.2 Finding Coterminal Angles
2.1.3 Finding the Complement and Supplement of an Angle
2.1.4 Converting between Degrees and Radians
2.1.5 Using the Arc Length Formula
2.2 Right Angle Trigonometry
2.2.1 An Introduction to the Trigonometric Functions
2.2.2 Evaluating Trigonometric Functions for an Angle in a Right Triangle
2.2.3 Finding an Angle Given the Value of a Trigonometric Function
2.2.4 Using Trigonometric Functions to Find Unknown Sides of Right Triangles
2.2.5 Finding the Height of a Building
2.3 The Trigonometric Functions
2.3.1 Evaluating Trigonometric Functions for an Angle in the Coordinate Plane
2.3.2 Evaluating Trigonometric Functions Using the Reference Angle
2.3.3 Finding the Value of Trigonometric Functions Given Information about the Values of Other Trigonometric Functions
2.3.4 Trigonometric Functions of Important Angles
2.4 Graphing Sine and Cosine Functions
2.4.1 An Introduction to the Graphs of Sine and Cosine Functions
2.4.2 Graphing Sine or Cosine Functions with Different Coefficients
2.4.3 Finding Maximum and Minimum Values and Zeros of Sine and Cosine
2.4.4 Solving Word Problems Involving Sine or Cosine Functions
2.5 Graphing Sine and Cosine Functions with Vertical and Horizontal Shifts
2.5.1 Graphing Sine and Cosine Functions with Phase Shifts
2.5.2 Fancy Graphing: Changes in Period, Amplitude, Vertical Shift, and Phase Shift
2.6 Graphing Other Trigonometric Functions
2.6.1 Graphing the Tangent, Secant, Cosecant, and Cotangent Functions
2.6.2 Fancy Graphing: Tangent, Secant, Cosecant, and Cotangent
2.6.3 Identifying a Trigonometric Function from its Graph
2.7 Inverse Trigonometric Functions
2.7.1 An Introduction to Inverse Trigonometric Functions
2.7.2 Evaluating Inverse Trigonometric Functions
2.7.3 Solving an Equation Involving an Inverse Trigonometric Function
2.7.4 Evaluating the Composition of a Trigonometric Function and Its Inverse
2.7.5 Applying Trigonometric Functions: Is He Speeding?

3. Trigonometric Identities

3.1 Basic Trigonometric Identities
3.1.1 Fundamental Trigonometric Identities
3.1.2 Finding All Function Values
3.2 Simplifying Trigonometric Expressions
3.2.1 Simplifying a Trigonometric Expression Using Trigonometric Identities
3.2.2 Simplifying Trigonometric Expressions Involving Fractions
3.2.3 Simplifying Products of Binomials Involving Trigonometric Functions
3.2.4 Factoring Trigonometric Expressions
3.2.5 Determining Whether a Trigonometric Function Is Odd, Even, or Neither
3.3 Proving Trigonometric Identities
3.3.1 Proving an Identity
3.3.2 Proving an Identity: Other Examples
3.4 Solving Trigonometric Equations
3.4.1 Solving Trigonometric Equations
3.4.2 Solving Trigonometric Equations by Factoring
3.4.3 Solving Trigonometric Equations with Coefficients in the Argument
3.4.4 Solving Trigonometric Equations Using the Quadratic Formula
3.4.5 Solving Word Problems Involving Trigonometric Equations
3.5 The Sum and Difference Identities
3.5.1 Identities for Sums and Differences of Angles
3.5.2 Using Sum and Difference Identities
3.5.3 Using Sum and Difference Identities to Simplify an Expression
3.6 Double-Angle Identities
3.6.1 Confirming a Double-Angle Identity
3.6.2 Using Double-Angle Identities
3.6.3 Solving Word Problems Involving Multiple-Angle Identities
3.7 Other Advanced Identities
3.7.1 Using a Cofunction Identity
3.7.2 Using a Power-Reducing Identity
3.7.3 Using Half-Angle Identities to Solve a Trigonometric Equation

4. Applications of Trigonometry

4.1 The Law of Sines
4.1.1 The Law of Sines
4.1.2 Solving a Triangle Given Two Sides and One Angle
4.1.3 Solving a Triangle (SAS): Another Example
4.1.4 The Law of Sines: An Application
4.2 The Law of Cosines
4.2.1 The Law of Cosines
4.2.2 The Law of Cosines (SSS)
4.2.3 The Law of Cosines (SAS): An Application
4.2.4 Heron's Formula
4.3 Vector Basics
4.3.1 An Introduction to Vectors
4.3.2 Finding the Magnitude and Direction of a Vector
4.3.3 Vector Addition and Scalar Multiplication
4.4 Components of Vectors and Unit Vectors
4.4.1 Finding the Components of a Vector
4.4.2 Finding a Unit Vector
4.4.3 Solving Word Problems Involving Velocity or Forces

5. Complex Numbers and Polar Coordinates

5.1 Complex Numbers
5.1.1 Introducing and Writing Complex Numbers
5.1.2 Rewriting Powers of i
5.1.3 Adding and Subtracting Complex Numbers
5.1.4 Multiplying Complex Numbers
5.1.5 Dividing Complex Numbers
5.2 Complex Numbers in Trigonometric Form
5.2.1 Graphing a Complex Number and Finding Its Absolute Value
5.2.2 Expressing a Complex Number in Trigonometric or Polar Form
5.2.3 Multiplying and Dividing Complex Numbers in Trigonometric or Polar Form
5.3 Powers and Roots of Complex Numbers
5.3.1 Using DeMoivre's Theorem to Raise a Complex Number to a Power
5.3.2 Roots of Complex Numbers
5.3.3 More Roots of Complex Numbers
5.3.4 Roots of Unity
5.4 Polar Coordinates
5.4.1 An Introduction to Polar Coordinates
5.4.2 Converting between Polar and Rectangular Coordinates
5.4.3 Converting between Polar and Rectangular Equations
5.4.4 Graphing Simple Polar Equations
5.4.5 Graphing Special Polar Equations

6. Exponential and Logarithmic Functions

6.1 Exponential Functions
6.1.1 An Introduction to Exponential Functions
6.1.2 Graphing Exponential Functions: Useful Patterns
6.1.3 Graphing Exponential Functions: More Examples
6.2 Applying Exponential Functions
6.2.1 Using Properties of Exponents to Solve Exponential Equations
6.2.2 Finding Present Value and Future Value
6.2.3 Finding an Interest Rate to Match Given Goals
6.3 The Number e
6.3.1 e
6.3.2 Applying Exponential Functions
6.4 Logarithmic Functions
6.4.1 An Introduction to Logarithmic Functions
6.4.2 Converting between Exponential and Logarithmic Functions
6.5 Solving Logarithmic Functions
6.5.1 Finding the Value of a Logarithmic Function
6.5.2 Solving for x in Logarithmic Equations
6.5.3 Graphing Logarithmic Functions
6.5.4 Matching Logarithmic Functions with Their Graphs
6.6 Properties of Logarithms
6.6.1 Properties of Logarithms
6.6.2 Expanding a Logarithmic Expression Using Properties
6.6.3 Combining Logarithmic Expressions
6.7 Evaluating Logarithms
6.7.1 Evaluating Logarithmic Functions Using a Calculator
6.7.2 Using the Change of Base Formula
6.8 Applying Logarithmic Functions
6.8.1 The Richter Scale
6.8.2 The Distance Modulus Formula
6.9 Solving Exponential and Logarithmic Equations
6.9.1 Solving Exponential Equations
6.9.2 Solving Logarithmic Equations
6.9.3 Solving Equations with Logarithmic Exponents
6.10 Applying Exponents and Logarithms
6.10.1 Compound Interest
6.10.2 Predicting Change
6.11 Word Problems Involving Exponential Growth and Decay
6.11.1 An Introduction to Exponential Growth and Decay
6.11.2 Half-Life
6.11.3 Newton's Law of Cooling
6.11.4 Continuously Compounded Interest

7. Conic Sections

7.1 Conic Sections: Parabolas
7.1.1 An Introduction to Conic Sections
7.1.2 An Introduction to Parabolas
7.1.3 Determining Information about a Parabola from Its Equation
7.1.4 Writing an Equation for a Parabola
7.2 Conic Sections: Ellipses
7.2.1 An Introduction to Ellipses
7.2.2 Finding the Equation for an Ellipse
7.2.3 Applying Ellipses: Satellites
7.2.4 The Eccentricity of an Ellipse
7.3 Conic Sections: Hyperbolas
7.3.1 An Introduction to Hyperbolas
7.3.2 Finding the Equation for a Hyperbola
7.3.3 Applying Hyperbolas: Navigation
7.4 Conic Sections
7.4.1 Identifying a Conic
7.4.2 Name That Conic
7.4.3 Rotation of Axes
7.4.4 Rotating Conics
Frequently Asked Questions for Thinkwell's Trigonometry

How do Thinkwell courses work?

Your student watches a 5-10 minute online video lesson and then completes the automatically graded exercises for the topic. You'll get instant correct-answer feedback. Then move on to the next lesson! The courses are self-paced, or you can use the daily lesson plans. Just like a textbook, you can choose where to start and end, or follow the standard table of contents.

When does my 12-month online subscription start?

It starts when you're ready. You can have instant access to your online subscription when you purchase online, or you can purchase now and start later.

What math courses should a student take?

A typical sequence of secondary math courses completed by a college-bound student is: Grade 6 Math > Grade 7 Math > Grade 8 Math > Algebra 1 > Geometry > Algebra 2 > Precalculus. For students looking to include Calculus as part of their high school curriculum and are able to complete Grade 7 Math in 6th grade, the sequence can be: Grade 7 Math > Prealgebra > Algebra 1 > Geometry > Algebra 2 > Precalculus > Calculus.

Is Thinkwell’s Trigonometry a college course?

Yes, but it is more commonly taught in high school.

Does my student get school credit for Thinkwell’s Trigonometry?

No, only schools are accredited and Thinkwell is not a school, though many accredited schools use Thinkwell.

Does Thinkwell Trigonometry meet state standards?

Some states set standards for what topics should be taught in a particular course. Thinkwell does not have a course version for each state. Instead, the course is built to national standards to be inclusive of all states. Websites such as can help you determine your state's standards.

What if my student needs access to the course for more than 12 months?

You can extend your subscription for $19.95/month.

Can I share access with more than one student?

The courses are designed and licensed to accommodate one student per username and password; additional students need to purchase online access. This allows parents to keep track of each student's progress and grades.

How long does it take to complete Thinkwell’s Trigonometry course?

The pace of your course is up to you, but most college students will schedule one semester.

Can I see my grade?

Thinkwell’s course software tracks everything your student does. When logged in, your student can click "My Grades" to see their progress.

How are grades calculated?

The course grade is calculated this way: Chapter Tests 33.3%, Midterm: 33.3%, Final: 33.3%.

What is acceptable performance on the exams?

As a homeschool parent, you decide the level of performance you want your student to achieve; the course does not limit access to topics based on performance on prior topics.

Can I get a transcript?

Yes, there's a final grade report print option in the My Grades section. Contact with any questions.

What if I change my mind and want to do a different math course, can I change?

If you discover that you should be in a different course, contact within one week of purchase and we will move you to the appropriate course.

Can I print the exercises?

Yes, but completing the exercises online provides immediate correct answer feedback and automatic scoring, so we recommend answering the exercises online.

Are exercises multiple choice?

Most of the exercises are multiple choice and they are graded automatically with correct answer solutions.

Is Thinkwell's Trigonometry Math built on "continuous review?"

Thinkwell's Trigonometry is carefully constructed to build on previous knowledge, reinforcing key concepts every step of the way. It is not only a reflection of empirically effective instruction, but also reflects Dr Burger’s philosophies learned over a career of teaching mathematics, emphasizing a solid foundation that addresses why students need to learn certain concepts. Finally, Thinkwell Trigonometry is intentionally designed to work for a wide variety of learning styles.

What is Thinkwell's Refund Policy?

We offer a full refund of 12-month subscription purchases within 14 days of purchase, no questions asked. For Essential Review courses, the refund period is 3 days. Optional printed materials are printed on demand and the sales are final.

How does my school review this course?

Should your school need to review a Thinkwell course for any reason, have the school contact and we can provide them access to a demo site.

Do I get credits for a Thinkwell course?

Generally, only schools can award credits, and Thinkwell is not a school. We can provide you with a certificate of completion and a grade report. However, if you’re pursuing credit with a particular school or institution, it might be helpful to know that Thinkwell math courses are accredited by the Western Association of Schools and Colleges (WASC) as a Supplementary Education Program. For California students, Thinkwell is also an approved A-G online publisher. Learn more about our accreditation HERE.

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