Lawrence Hall of Science
The Math Page: Trigonometry
Concepts in Trigonometry are explained and illustrated here by a member of the math department at Borough of Manhattan Community College.
Other
Gcse Answers' Easy Start Trigonometry
Some basic questions dealing with everyday situations where trigonometry is needed to solve the problem. Click a button for the solutions.
Mathigon
Mathigon: Geometry: Triangles and Trigonometry: Trigonometry
This lesson focuses on trigonometry including the trigonometric functions: sine, cosine, and tangent.
Illustrative Mathematics
Illustrative Mathematics: F Tf Sum and Difference Angle Formulas
The goal of this task is to have learners derive the addition and subtraction formulas for cosine and tangent, and the subtraction formula for cosine, from the sum formula for sine. Aligns with F-TF.C.9.
Illustrative Mathematics
Illustrative Mathematics: F tf.a, F bf.b.3 Exploring Sinusoidal Functions
In this task, students explore the effect that changing the parameters in a sinusoidal function has on the graph of the function. Aligns with F-TF.A and F-BF.B.3.
Illustrative Mathematics
Illustrative Mathematics: F Tf Equilateral Triangles and Trigonometric Functions
The purpose of this task is to apply knowledge about triangles to calculate the sine and cosine of 30 and 60 degrees. Aligns with HSF-TF.A.3.
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.
University of St. Andrews (UK)
University of St. Andrews: Albert Girard
In trigonometry today, we use the abbreviations sin, cosine and tan. Girard was the first mathematician to use these abbreviations in his work.
Khan Academy
Khan Academy: Trigonometry: Evaluate Inverse Trig Functions
Given a sine, cosine, or tangent value, find the principle angle that has this value. In other words, find the arcsine, arccosine, or arctangent of that value. Students receive immediate feedback and have the opportunity to try questions...
Khan Academy
Khan Academy: Algebra Ii: Trig Values of Special Angles
Find the sine and cosine of special angles, which are angles whose trig values we can determine without the use of a calculator. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or...
Khan Academy
Khan Academy: Midline of Sinusoidal Functions From Equation
Given the formula of a sinusoidal function, determine its midline equation. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Graph Sinusoidal Functions
Given the formula of a sinusoidal function of the form a*f(bx)+d, draw its graph. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Algebra Ii: Modeling With Sinusoidal Functions
Given the description of a real-world relationship, find the sinusoidal function that models it. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Algebra Ii: Use the Pythagorean Identity
Given the sine (or cosine) of an angle, find its cosine (or sine) using the Pythagorean identity. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Algebra Ii: Construct Sinusoidal Functions
Given a few features of a sinusoidal function, find its formula. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Trigonometry: Introduction to the Triangle Area Formula
[Free Registration/Login may be required to access all resource tools.] This lesson covers how to find the area of a triangle using sine.
CK-12 Foundation
Ck 12: Trigonometry: Sine, Cosine, and Tangent Functions
[Free Registration/Login may be required to access all resource tools.] This lesson covers the three trigonometric ratios: sine, cosine, and tangent.
CK-12 Foundation
Ck 12: Trigonometry: Sine Sum and Difference Formulas
[Free Registration/Login may be required to access all resource tools.] Sine of a sum or difference related to a set of cosine and sine functions. Here you'll learn to rewrite sine functions with addition or subtraction in their...
CK-12 Foundation
Ck 12: Trigonometry: Horizontal Translations or Phase Shifts
[Free Registration/Login may be required to access all resource tools.] Defining horizontal translations of sine and cosine functions.
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.