Trigonometry Chapter 2
2.1 Trigonometric Functions of Acute Angles
pg. 46
Objective: All students will analyze Trig Functions, Cofunction Identities, 30-60-90
Triangles, and 45-45-90 Triangles.
I. Trigonometry Functions
A. What are the Right-Triangle-Based Definitions of the Trig Functions? Draw a
diagram illustrating these definitions.
B. Show an example using these definitions.
II. Cofunctions
A.
B.
C.
D.
E.
List the cofunctions.
Illustrate why cofunctions exist.
List the cofunction identities.
Explain the existence of cofunction identities.
Show five examples of using the concept of cofunction identities.
III. Angle increases
A. What happens to the trig functions as an angle A increases in size.
B. Show two examples.
IV. 30-60-90 Triangle
A. Illustrate how a 30-60-90 Triangle is formed from an Equilateral Triangle.
B. Based on your triangle, find the Trig Functions for 30°
V. 45-45-90 Triangle
A. Illustrate a 45-45-90 Triangle.
B. Find the Trig Functions for 45°
C. Why can’t you use a calculator to find trig functions of special angles?