Interactive
Curated OER

Trig Function Point Definitions

For Students 9th - 10th Standards
A java applet that relates the unit circle to the graphs of the six trigonometric functions, complete with the values of the functions.
Activity
Other

North Carolina Su: Triangles, Circles, and Waves (Oh My!)

For Students 9th - 10th Standards
This site has a basic overview of trigonometry focusing on the trig functions, trig ratios, and the unit circle.
Handout
Wolfram Research

Wolfram Math World: Trigonometric Addition Formulas

For Students 9th - 10th Standards
This tutorial offers formulas and explanations on trigonometric addition formulas and features an easy way to remember the sine and cosine addition formulas using matrices.
Activity
Hofstra University

Hofstra University: Modeling the Sine Function

For Students 9th - 10th
Extensive information on the sine function and links to the other trigonometric functions. The site includes definitions of properties of the sine function and various examples involving them. Also includes a number of real world...
Unit Plan
CK-12 Foundation

Ck 12: Trigonometry: Sine, Cosine, and Tangent Functions

For Students 10th - 12th Standards
[Free Registration/Login may be required to access all resource tools.] Calculate sine, cosine, and tangent functions using the sides of a right triangle.
Handout
University of Guelph

University of Guelph: Trigonometry Tutorial

For Students 9th - 10th Standards
A guide to calculating trigonometric functions.
Handout
Other

Dans Math: Lessons: Trigonometry

For Students 9th - 10th
College professor Dan Bach reviews basic trig concepts, including trig functions, right triangles, circles, radians, and polar coordinates. Site includes animated graphs and detailed examples.
Activity
Interactive Mathematics

Interactive Mathematics: Trigonometric Functions

For Students 9th - 10th Standards
This is a excellent review lesson about trigonometric functions of any angle. Good examples here.
Activity
Math Is Fun

Math Is Fun: Triangle Identities

For Students 9th - 10th Standards
View examples of triangle identities, equations that are true for all triangles: Law of Sines, Law of Cosines, and Law of Tangents. Follow links to learn more about the purpose and examples of each identity.
Handout
Purple Math

Purplemath: Special Angle Values: 30 60 90 and 45 45 90 Triangles

For Students 9th - 10th
Explains a simple pictorial way to remember basic reference angle values. Provides other memory aids for the values of trigonometric ratios for these "special" angle values, based on 30-60-90 triangles and 45-45-90 triangles.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Srt, G Mg Seven Circles Iii

For Teachers 9th - 10th Standards
For this task, learners are shown circle formations where an inner circle is surrounded by a set of circles and all circles are touching. In the first situation, all circles have the same diameter. In the second, the inner circle is...
Unit Plan
Northeast Parallel Architectures Center, Syracuse University

Npac Reu Program: Derivatives of Trigonometric Functions

For Students 11th - 12th
This Northeast Parallel Architectures Center at Syracuse University site is a table of contents for information and examples on derivatives of trigonometric functions.
Activity
University of Vienna (Austria)

Maths Online: Recognize Functions 3

For Students 9th - 10th Standards
An excellent place to test your ability to recognize the graphs of sine and cosine and their various associated forms. A Java applet is also included to plot your own function.
Activity
Math2

Math2: Trigonometric Graphs

For Students 9th - 10th
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.
Activity
Interactive Mathematics

Interactive Mathematics: Sine, Cosine, Tan & Reciprocals

For Students 9th - 10th Standards
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.
Unit Plan
University of California

University of California, Davis:trig Derivatives

For Students 9th - 10th
Use this site from the University of California, Davis to practice taking derivatives of trigonometric functions. The site begins with a list of the derivatives of each of the trig functions and then offers related problems with solutions.
Activity
Math Medics

S.o.s. Math: Trigonometric Functions

For Students 9th - 10th Standards
Introductory lesson to trigonometric functions. Includes definitions, properties, graphs, and a wide variety of examples and practice exercises.
Handout
Johan Claeys

Math Abundance: Trigonometry: The Sine Function

For Students 9th - 10th Standards
Definition of a sine function. Range and period also are given. Graph of sine function given as well.
Activity
Windstream

Ojk's Precalculus Study Page: Evaluating and Graphing Sine and Cosine

For Students 9th - 10th Standards
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.
Handout
Wolfram Research

Wolfram Math World: Trigonometric Functions

For Students 9th - 10th Standards
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.
Handout
Windstream

Ojk's Precalculus Study Page: More Difficult Trig Equations

For Students 9th - 10th Standards
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.
Website
Other

Inverse Trigonometric Functions [Pdf]

For Students 9th - 10th Standards
This is a ten page selection from a math textbook that highlights the concept of inverse trigonometric functions. The book provides real world examples, worked out practice problems and numerous problems for students to attempt on their...
Activity
Windstream

Ojk's Precalculus Study Page: The Law of Sines

For Students 9th - 10th Standards
An introduction to solving acute and obtuse triangles by using the law of sines, including a derivation of the formula. Includes several pictures and examples.
Graphic
Math2

Math2.org: Trigonometry Tables

For Students 9th - 10th Standards
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)...