Interactive Mathematics
Interactive Mathematics: Sine, Cosine, Tan & Reciprocals
The definitions of the six trig ratios are presented here, along with several examples of how to determine the ratios given 2 or more sides of a right triangle.
Oswego City School District
Regents Exam Prep Center: Working on a Rescue Team Lab
Your students are part of the Yellowstone National Park rescue team which has just been dispatched to help located a downed plane. How can they effectively use the Law of Sines and the Law of Cosines to assist them in finding the plane?...
Interactive Mathematics
Interactive Mathematics: Trigonometric Functions
This is a excellent review lesson about trigonometric functions of any angle. Good examples here.
Interactive Mathematics
Interactive Mathematics: Trigonometric Functions
Just about everything you need to know about trigonometry can be found here. Interactive examples and demonstrations help to enhance the lessons. Although not required, the tutorial uses Live Math and Scientific Notebook.
Math Open Reference
Math Open Reference: Derivatives of the Trigonometric Functions
Gain an understanding of the derivatives of the six common trigonometric functions with this helpful reference tool. Provides a detailed definition and examples that enhance further explanation. Includes links to related topics.
eFunda
E Funda: Multiple Angle
At this site from eFunda you can scroll to the middle of the page for a listing of multiple angle formulas for cos, sin, and tan.