Ch 31: ACT Math: Trigonometry

About This Chapter

Go over basic trigonometry topics to get ready for the college-entry ACT math test. Use our short video lessons and quizzes for an informative review.

ACT Math: Trigonometry - Chapter Summary

By working your way through the lessons and quizzes, you can easily review these important trigonometry topics to prepare for the ACT:

  • Sine and cosine
  • Basic trigonometric identities
  • Trigonometric functions and exponentials on calculators
  • Pythagorean theorem and trigonometry
  • Radians and degrees: conversions and understanding on scientific calculators

This chapter also includes practice in how to find 'x' by solving trigonometric equations. Review all of these topics through our short, user-friendly videos and quizzes.

ACT Math Objectives

The math section of the ACT test is a 60-minute, 60-question exam. The multiple-choice questions analyze your reasoning skills in the solutions of math problems. In general, the math test includes these six content areas:

  • Trigonometry
  • Coordinate geometry
  • Plane geometry
  • Pre-algebra
  • Elementary algebra
  • Intermediate algebra

The trigonometry portion of the math test makes up 7% of the questions. The testing focuses on the following crucial areas:

  • Trigonometric relations in right triangles
  • Properties and values of trigonometric functions
  • Trigonometric functions in graphing and modeling
  • Trigonometric identities and equations

You'll get four scores for the math test, including an overall score for all 60 questions, followed by sub-scores in plane geometry/trigonometry, pre-algebra/elementary algebra and intermediate algebra/coordinate geometry. A set of 18 problems forms the basis for the plane geometry/trigonometry sub-score.

9 Lessons in Chapter 31: ACT Math: Trigonometry
Trigonometry: Sine and Cosine

1. Trigonometry: Sine and Cosine

Learn an easy trick to help you solve trigonometry problems, including problems with sine, cosine and inverse trig functions. At the end of this lesson, you'll know what SohCahToa means and how to use it.

Converting Between Radians and Degrees

2. Converting Between Radians and Degrees

Angles can be measured in degrees or radians. This lesson will explore the difference and provide you with a simple calculation that can be used to convert degrees into radians and radians into degrees.

How to Solve Trigonometric Equations for X

3. How to Solve Trigonometric Equations for X

Adding trigonometric functions into standard algebra equations adds complexity. Learn how to solve trigonometric equations for x and how to use inverse operations to simplify equations.

List of the Basic Trig Identities

4. List of the Basic Trig Identities

There are specific trig functions that have very special and very simple relationships with each other. Learn the main one and how you can use it to understand the others.

Trigonometry and the Pythagorean Theorem

5. Trigonometry and the Pythagorean Theorem

Explore how the Pythagorean Theorem can be used in conjunction with trigonometric functions. In this lesson, take an inverse trigonometric function, and define all three sides of a right triangle.

Trigonometry Functions & Exponentials on a Calculator

6. Trigonometry Functions & Exponentials on a Calculator

Despite the fact that you've probably used a scientific calculator since middle school, it's really only in high school and college that you learn what all the keys are for. In this lesson, we look at trigonometric functions and exponential keys.

Trigonometry Functions & Exponentials on the CLEP Calculator

7. Trigonometry Functions & Exponentials on the CLEP Calculator

In this lesson, review how to use the history on the CLEP calculator as we calculate sines, cosines and the inverse trigonometric functions. Finish by exploring exponentials and logarithms.

Radians & Degrees on a Calculator

8. Radians & Degrees on a Calculator

While we may have a tendency to think of angles solely in terms of degrees, the truth is that radians offer a useful way of looking at them. However, being able to switch between the two is crucial for making the most of having a calculator.

Radians & Degrees on the CLEP Scientific Calculator

9. Radians & Degrees on the CLEP Scientific Calculator

In this lesson, we'll review online calculators, in particular the CLEP online calculator. Review the difference between radians and degrees, the order of operations and scientific notation on the CLEP calculator.

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