Purple Math
Purplemath: Special Angle Values: 30 60 90 and 45 45 90 Triangles
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.
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.
CK-12 Foundation
Ck 12: Exact Values for Inverse Sine, Cosine, and Tangent
[Free Registration/Login may be required to access all resource tools.] Find all angles on the unit circle matching exact trig ratios. Resource includes examples, videos, and practice problems.
CK-12 Foundation
Ck 12: Trigonometry: Period and Frequency
[Free Registration/Login may be required to access all resource tools.] Relating period and frequency for a sine or cosine graph with examples, practice problems, and vocabulary.
CK-12 Foundation
Ck 12: Trigonometry: Trigonometric Identities and Equations
[Free Registration/Login may be required to access all resource tools.] Describe general forms and graphs for cosine and sine equations.
Alabama Learning Exchange
Alex: The Clock Tower
This project resulted from the collaboration of a computer aided drafting teacher (pre-engineering), Chris Bond, and a math teacher, Lee Cable, (Hewitt-Trussville High School) to provide higher math expectations in CT and real life...
Khan Academy
Khan Academy: Start Here! Ready to Dive Into Some More Math?
This is an overview of the activity: Young scholars are going to derive a powerful formula which will calculate where any point (x,y) (x, y) (x,y)left parenthesis, x, comma, y, right parenthesis goes afterrotation by an angle theta theta...
Cool Math
Coolmath: Solving Trig Equations
This CoolMath resource explains how to solve trigonometric equations
Math Open Reference
Math Open Reference: Trigonometry Functions Introduction
A complete reference guide to trigonometry functions. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Cuemath
Cuemath: Cosine Law
A comprehensive guide for learning all about the law of cosine with definitions, what is the law, and solved examples.
CK-12 Foundation
Ck 12: Algebra Ii: 4.8 Pythagorean Identities
This section explores the Pythagorean Identity and how it applies to right triangles set inside unit circles, in terms of sine, cosine, and tangent functions.
CK-12 Foundation
Ck 12: Algebra Ii: 4.6 Transformations of Trigonometric Functions
Explore how changes to the equations of sine and cosine functions affect the graphs of the functions through transformations (stretches and shifts).
CK-12 Foundation
Ck 12: Algebra Ii: 4.5 Graphing Sine and Cosine
This section explores the graphs of sine and cosine functions. It investigates how these graphs are related to coordinates for different angles in a unit circle.
CK-12 Foundation
Ck 12: Interactive Geometry: 7.3 Sine and Cosine of Complementary Angles
Explore the sine and cosine of complementary angles.
CK-12 Foundation
Ck 12: Interactive Geometry: 7.2 Sine and Cosine Ratios
Discover sine and cosine ratios in trigonometric ratios.
Math Open Reference
Math Open Reference: Cosine (Cos) Function Trigonometry
A complete reference guide to the cosine function in trigonometry. It provides definitions, examples, and an interactive activity that enhances further explanation.
Purple Math
Purplemath: Quadrants and Angles
Explains how to model angles in the x,y-plane, and demonstrates how to extend the concept of trig ratios to angles larger than 90 degrees.
Purple Math
Purplemath: Trigonometric Identities
Lists the basic trigonometric identities, and specifies the set of trig identities to keep track of, as being the most useful ones for calculus.
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: 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.
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: 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.
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.