University of Saskatchewan (Canada)
University of Saskatchewan: Trigonometric Functions
This site examines the six trigonometric functions from a right triangle point of view. Provides information, examples, and lots of exercises for understanding.
Northeast Parallel Architectures Center, Syracuse University
Npac Reu Program: Trig Function Graphs
Northeast Parallel Architectures Center provides a quick overview of the graphs of the six trigonometric functions, with angles measured in radians.
Northeast Parallel Architectures Center, Syracuse University
Npac Reu Program: Trigonometric Functions
This Northeast Parallel Architectures Center of Syracuse University site offers a quick overview of the six trigonometric functions from the standpoint of the unit circle.
Clark University
Clark University: Dave's Short Trig Course: Summary of Trig Identities
This Clark University page is an excellent reference page for trig identities. It is a little difficult to read so take your time with the formulas. If you remember soh - cah - toa, the other formulas are right here.
University of St. Andrews (UK)
University of St. Andrews: Trigonometric Functions
This site from the University of Saint Andrews provides an historical look at the origins of trig functions. This site ties together mathematics and history from Hipparchus to Ptolemy to Lambert.
Purple Math
Purplemath: Solving Simple (To Medium Hard) Trig Equations
Introduces techniques for solving trigonometric equations. Provides worked examples of solving some simpler to medium-hard equations.
Curated OER
Zona Land: Overlapped Graph of the Six Trig Functions
An overview of the six trig functions and their graphs. The site is a little difficult to navigate but is good for finding a graph of a trig function.
Math2
Math2.org: Trigonometry Tables
Three trig tables are provided for student and teacher reference. The first table lists the sine, cosine, tangent, secant, cosecant, and cotangent values of all whole-number angles from 0 to 90. The radian equivalent (to four decimals)...
Wolfram Research
Wolfram Math World: Cosecant
Graphs of the cosecant function, both 2-dimensional and 3-dimensional. This site from Math World tells the relation between cosecant and sine. If you are not familiar with the sine function there is a link for a better understanding....
Wolfram Research
Wolfram Math World: Trigonometry
This site provides a good definition of trigonometry. Includes many links to key terms and many more to related terms. This site may be used as a refresher for students who have finished the course, or students currently studying the...
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.
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.