Clark University
Clark University: Dave's Short Trig Course: Trigonometric Functions
The Clark University site shows and explains the graphs of the six trigonometric functions. It explains how to find an arbitrary angle measurement using trig. Also, it explains that sine and cosine functions are complementary.
BBC
Bbc: Radians and Equations
BBC provides a tutorial that explains how radians are related to degrees and demonstrates how to solve trig equations in radian units. Examples and a practice test are available.
Interactive Mathematics
Interactive Mathematics: Graphs of Sine and Cosine Functions
An interactive graph provides a demonstration to show how the measure of an angle is related to the sine and cosine waves. Topics covered include amplitude and period. Examples allow students to practice the concepts.
Math2
Math2: Trigonometric Graphs
Sketches of the graphs of the 12 "parent," trigonometry functions are given: sine, cosine, tangent, secant, cosecant, cotangent, arcsine, arccosine, arctangent, arcsecant, arccosecant, and arccotangent.
Other
Personal Site: Sine and Cosine Do "The Wave"
This personal site provides a great animation of how the sine and cosine waves are formed. It connects the unit circle with the sine and cosine graph.