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Lesson Plan
EngageNY

Proving Trigonometric Identities

For Teachers 10th - 12th Standards
Young mathematicians first learn the basics of proving trigonometric identities. They then practice this skill on several examples.
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Lesson Plan
EngageNY

The Definition of Sine, Cosine, and Tangent

For Students 9th - 10th Standards
Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar triangles. 
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Worksheet
Curated OER

6.5 Skill Builder: Trigonometric Identities

For Students 9th - 12th
In this trigonometric identities worksheet, students solve 16 multi-part short answer problems. Students use the quotient identity and Pythagorean identity to simplify trigonometric expressions. Students factor trigonometric expressions.
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Instructional Video20:40
2
2
Flipped Math

Modeling with Trig Functions

For Students 9th - 12th Standards
Find out what to do with Ferris wheels that keep going up and down. Individuals learn how to determine the frequency of a trigonometric function. Pupils use their knowledge of trigonometric functions to model periodic motions like Ferris...
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Lesson Plan
EngageNY

Basic Trigonometric Identities from Graphs

For Students 10th - 12th Standards
Have young mathematicians create new identities! They explore the even/odd, cofunction, and periodicity identities through an analysis of tables and graph. Next, learners discover the relationships while strengthening their understanding...
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Lesson Plan
Alabama Learning Exchange

"I Saw the Sine"

For Teachers 9th - 12th Standards
Discover trigonometric ratios that complement each other. Using two videos, the lesson introduces the trigonometric ratios. The class discovers the relationship between the sine and cosine of complementary angles.
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Instructional Video20:08
2
2
Flipped Math

Trig Ratios

For Students 9th - 12th Standards
Take ratios of sides to a new level. Pupils learn the definitions of the three basic trigonometric ratios in right triangles. Using the definitions, scholars find missing lengths in right triangles, based on a known angle. Individuals...
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Worksheet
Curated OER

Finding Trigonometric Ratios

For Students 11th
In this finding trigonometric ratios worksheet, 11th graders solve and complete 22 various types of problems. First, they find the value of each trigonometric ratio to the nearest ten-thousandth. Then, students use a calculator to find...
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Lesson Plan
Project Maths

Trigonometric Functions

For Teachers 9th - 12th Standards
From a circle to a cycle! The final lesson of a five-part series challenges learners to use points from the unit circle to plot a repeating pattern. The repeating patterns become the graphs of the trigonometric functions. Scholars also...
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Lesson Plan
EngageNY

Properties of Trigonometric Functions

For Teachers 11th - 12th Standards
Given a value of one trigonometric function, it is easy to determine others. Learners use the periodicity of trigonometric functions to develop properties. After studying the graphs of sine, cosine, and tangent, the lesson connects them...
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Lesson Plan
Curated OER

Does Your Field Measure Up

For Teachers 9th - 11th
Learners measure angles using a plane table kit. In this geometry lesson, students use trigonometric identities to find the values of the length of a football field.
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Lesson Plan
EngageNY

What Is a Trigonometric Identity?

For Students 10th - 12th Standards
Protect yourself from identity theft! Establishing a strong understanding of the Pythagorean identity allows learners to prove that sine^2x + cos^2x = 1. They then use the identity to find sine or cosine ratios given the other.
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Lesson Plan
Curated OER

Proof of Identity

For Teachers 9th - 12th Standards
Students explore trigonometric identities.   In this Algebra II lesson, students use graphing to verify the reciprocal identities.  Using Cabri Jr, students investigate the Pythagorean trigonometric identities and the geometric c proofs...
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Interactive
CK-12 Foundation

Basic Trigonometric Functions: Ladder Length

For Students 9th - 12th Standards
Climb the ladder to trigonometry. The interactive introduces trigonometric ratios and finding lengths of sides of right triangles created by a ladder and a building. Learners use the interactive to create triangles by moving the top of...
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Lesson Plan
West Contra Costa Unified School District

Introduction to Trigonometric Functions

For Teachers 9th - 12th
Scholars first learn the definitions of the sine ratio, the cosine ratio, and the tangent ratio. After mastering these definitions, they use the new information to solve triangles.
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Interactive
CK-12 Foundation

Derivatives of Trigonometric Functions: Derivative of sin(x)

For Students 11th - Higher Ed
Graphically find the derivative of sin(x). Using the interactive, pupils graph the slope of the tangent line to the sine function. Class members use the resulting graph to determine the derivative of the sine function. They verify their...
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Interactive
PHET

Trig Tour

For Students 9th - 12th Standards
Unit circles and trigonometric graphs go hand in hand. Pupils see how traversing the unit circle allows for the creation of graphs for trigonometric functions. They also see trigonometric ratios in terms of the ordered pairs of points on...
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Worksheet
Curated OER

Trigonometric Ratios

For Students 10th - 12th
In this trigonometric ratios worksheet, students determine the value of trigonometric ratios.  They find the area of triangles, determine the length of one side, and compute the degrees in an angle.  This five-page worksheet contains 55...
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Lesson Plan
West Contra Costa Unified School District

Law of Sines

For Teachers 10th - 12th Standards
One must obey the sine laws. A lesson introduces and derives the Law of Sines for non-right triangles. With examples that use the Law of Sines to determine unknown measures in triangles, the lesson checks to see if the Law of Sines also...
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Worksheet
2
2
Mt. San Antonio Collage

Graphing Trigonometric Functions

For Students 9th - 12th Standards
Double win with a comprehensive worksheet and an excellent worked out answer key. The worksheet itself is twelve pages and begins with the simple sine and cosine graphs, then, develops into the reciprocal trig functions. 
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Lesson Plan
Curated OER

Graphs of the OTHER Trig Functions

For Teachers 10th - 11th
Learners graph trigonometric functions. For this precalculus lesson, students identify the properties of secant ,cosecant and cotangent. They use the unit circle as their formula to graph and analyze these functions.
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Lesson Plan
EngageNY

Solving Problems Using Sine and Cosine

For Students 9th - 10th Standards
Concepts are only valuable if they are applicable. An informative resource uses concepts developed in lessons 26 and 27 in a 36-part series. Scholars write equations and solve for missing side lengths for given right triangles. When...
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Lesson Plan
West Contra Costa Unified School District

Law of Sines

For Teachers 9th - 12th Standards
Laws are meant to be broken, right? Learners derive the Law of Sines by dropping a perpendicular from one vertex to its opposite side. Using the Law of Sines, mathematicians solve for various parts of triangles.
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Lesson Plan
EngageNY

Trigonometric Identity Proofs

For Teachers 10th - 12th Standards
Proving a trig identity might just be easier than proving your own identity at the airport. Learners first investigate a table of values to determine and prove the addition formulas for sine and cosine. They then use this result to...