1. An Introduction to Trigonometry Slideshow 44, Mathematics Mr. Richard Sasaki, Room 307

2. ObjectivesObjectives

3. The Right-Angled Triangle Trigonometry is like Pythagoras but includes angles. When we have a specified angle, the vocabulary is different. Angle (Theta) Hypotenuse Opposite Adjacent Simple trigonometry involves 2 edges and an angle. If one thing is missing, how do we find it?

4. Special Case Triangles We saw two basic cases, the 30-60-90 triangle and the 45-45-90 triangle. We need to think about the relationship between the edge lengths and the angles. Any ideas? The relationship lies with the three main trigonometric functions,, and. sinecosinetangent

5. Sine, Cosine and Tangent Sine, cosine and tangent are the relationships between edge lengths and angles. Each refer to two of the edges. Hypotenuse Opposite Adjacent Sine Cosine Tangent S O H C A H T O A You will need to remember these links.

6. Sine, Cosine and Tangent In fact, sine, cosine and tangent are functions on angles which equates to the ratio of the corresponding two edges. Hypotenuse Opposite Adjacent

7. hypotenuse adjacent opposite

8. Trigonometric Functions

9. BoundariesBoundaries We do not have time to explore further but after looking at many values inserted in the trigonometric functions, we would have the following boundaries:

10. Note: We are using degrees, not radians.

12. The sizes are increasing. There is a cycle however…like this: