Khan Academy
Khan Academy: Intro to Inverse Trig Functions
Learn about arcsine, arccosine, and arctangent, and how they can be used to solve for a missing angle in right triangles.
Purple Math
Purplemath: Inverses of Trigonometric Ratios
You know that you can take side lengths and find trig ratios, and you know you can find trig ratios (in your calculator) for angles. What is missing is a way to go from the ratios back to the original angles. And that is what "inverse...
Purple Math
Purplemath: The Unit Circle
Relates the unit circle to the method for finding trig ratios in any of the four quadrants. Demonstrates how the unit circle might be useful.
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 Functions
A complete look at trig functions. From an "overview," page giving general definitions and important vocab words, to a listing of the 12 trig functions, to an explanation of the three modes used in trigonometry, to the procedures of how...
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: Secant
Graphs of the secant function, both 2-dimensional and 3-dimensional. The site from MathWorld gives the relation of secant to cosine, if you are not familiar with cosine there is a link for an understanding.
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: Cotangent
Graphs of the cotangent function, both 2-dimensional and 3-dimensional. Higher level mathematics applications given including the Macluarin series.
Wolfram Research
Wolfram Math World: Trigonometric Functions
This site provides a listing of the trigonometric functions and their inverses. Their notation is also addressed along with links to each of the fundamental trigonometric functions.
Windstream
Ojk's Pre Calculus Study Page: The Four Other Trig Functions
Trigonometry ratios and their signs are given in this explanation of the other trig functions. Graphs of tangent, cotangent, secant, and cosecant are given. Examples are included.
Wolfram Research
Wolfram Math World: Trigonometric Functions
This site from MathWorld.com is a site full of links to very extensive documentation on the trigonometric functions.
Windstream
Ojk's Precalculus Study Page: Trigonometry Sample Test
A practice test that covers proving trigonometric identities and solving advances trigonometric equations.
Windstream
Ojk's Precalculus Study Page: More Difficult Trig Equations
An introduction to solving trigonometric equations by using the reciprocal, negative, Pythagorean, and cofunction identities. Includes several examples and exercises with solutions at the bottom of the page.
Math Medics
S.o.s. Math: Trigonometry
This lesson is the main SOS Math page for trigonometry. Surf the lesson to find most any trigonometric identity, formula, and many forms of help in the area of trigonometry.
Math Words
Math Words: Cofunction Identities
This MathWords.com site, which is a glossary of math terms, shows the relationship in radians and degrees between sin and cos, tan and cot, and sec and csc.
Math Medics
S.o.s. Math: Trigonometric Functions
Introductory lesson to trigonometric functions. Includes definitions, properties, graphs, and a wide variety of examples and practice exercises.
Mr. Martini's Classroom
Mr. Martini's Classroom: Right Angle Trigonometry
Explore sine, cosine, and tangents compared to the selected angle.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Trigonometric Ratios
Find a quick, concise explanation of the trigonometric ratios: sine, cosine and tangent. Examples are given and clearly explained.
Interactive Mathematics
Interactive Mathematics: Trigonometric Functions of Any Angle
Given a reference angle, you can find the trigonometric functions of any angle. The process is demonstrated in this lesson and examples are provided for practicing the concept.
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.
That Quiz
That Quiz: Trigonometry
You can practice evaluating the six trigonometric functions and their inverse in radians or degrees. Four different levels are provided and it also tracks the number of correct answer.
Windstream
Ojk's Precalculus Study Page: Evaluating and Graphing Sine and Cosine
An introduction to graphing the sine and cosine functions by using the 30-60-90 and 45-45-90 right triangle values of the two functions as guides.
Walter Fendt
Walter Fendt: Sine, Cosine and Tangent of an Angle
A short interactive activity to visualize the trigonometric functions: sine, cosine, and tangent.