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.
Illustrative Mathematics
Illustrative Mathematics: F Tf Trig Functions and the Unit Circle
The purpose of this task is to help students make the connection between the graphs of sin t and cos t and the x and y coordinates of points moving around the unit circle. Students have to match coordinates of points on the graph with...
Illustrative Mathematics
Illustrative Mathematics: F Tf Special Triangles 1
Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.
Illustrative Mathematics
Illustrative Mathematics: F Tf Properties of Trigonometric Functions
The goal of this task is to use the unit circle and rigid transformations in order to establish some fundamental trigonometric function identities. Aligns with F-TF.A.2 and F-TF.A.4.
Illustrative Mathematics
Illustrative Mathematics: F Tf Trigonometric Functions for Arbitrary Angles
The purpose of this task is to examine trigonometric functions for obtuse angles. Aligns with F-TF.A.2.
Illustrative Mathematics
Illustrative Mathematics: F Tf Special Triangles 2
Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.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.
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...
Mathigon
Mathigon: Geometry: Circle and Pi: Degrees and Radians
Rather than dividing a circle into some number of segments (like 360 degrees), mathematicians often prefer to measure angles using the circumference of a unit circle - a circle with radius 1. This way of measuring angles is called...
CK-12 Foundation
Ck 12: Trigonometry: Conversion Between Degrees and Radians
[Free Registration/Login may be required to access all resource tools.] This lesson introduces the unit circle and radians.
CK-12 Foundation
Ck 12: Trigonometry: Tangent and Cotangent Graphs
[Free Registration/Login may be required to access all resource tools.] Define the tangent and cotangent graphs using the unit circle.
CK-12 Foundation
Ck 12: Trigonometry: Trigonometric Functions and Angles of Rotation
[Free Registration/Login may be required to access all resource tools.] Describing trig functions as relationships on the unit circle.
Alabama Learning Exchange
Alex: Traveling Around the Unit Circle
This instructional activity is intended to review the key ideas associated with trigonometric functions.The design of this instructional activity provides a collection of reproducible activities to be used in a classroom setting where...
CK-12 Foundation
Ck 12: Algebra Ii: 4.3 the Unit Circle
Activities in this lesson explore how to identify the coordinates where special right triangles intersect with the unit circle in all four quadrants, use both degrees and radians to identify angles, and explore angles of different sizes...
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.
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)...
Other
Personal Site: Sine and Cosine Do "The Wave"
This personal site provides a great animation of how the sine and cosine waves are formed. It connects the unit circle with the sine and cosine graph.
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: The Unit Circle
Eight problems present a variety of practice working with unit circles. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution" button to check...
National Council of Teachers of Mathematics
The Math Forum: Vectors
This site from the Math Forum of Drexel University contains downloadable sketches and pictures related to vectors. You may need to down-load the Geometer's Sketchpad to view these pages.