# Trigonometric Functions

by M. Bourne

## Why learn about trigonometric functions...?

**Example problem:**

How high above sea level is the top of the Sydney Opera House? Have you ever thought about how to
**measure** that height?

The** trigonometric functions** are very important in technical subjects like science, engineering,
architecture, and even medicine. You will come across trig functions all the time and you are encouraged to learn them well!

**Surveying** is one of the many applications. Road makers, bridge builders and those whose job it is to
get buildings in the right place all use trigonometry in their daily work.

Continue reading below ⇩

In this chapter we start by explaining the basic trigonometric functions using degrees (°), and in the later part of the chapter we will learn about radians and how they are used in trigonometry.

### Search IntMath, blog and Forum

Chapter menu below ⇩

Chapter Contents

- Trigonometric Functions
- 1. Angles
- 2. Sine, Cosine, Tangent & Reciprocals
- 3. Values of Trigonometric Functions
- 4. The Right Triangle and Applications
- 4a. Trigonometry Revision Summary
- 5. Signs of the Trigonometric Functions
- 6. Trigonometric Functions of Any Angle
- 7. Radians
- 8. Applications of Radian Measure
- 8a. Pulleys
- 9. Radians and the Trigonometric Ratios