Unit Circle and Trigonometric Functions

Lesson 8

Math

Unit 6

11th Grade

Lesson 8 of 14

Objective


Evaluate transformations of sine, cosine, and tangent such as $${2{\pi-x}}$$$${\pi-x}$$, and $${\pi+x}$$.

Common Core Standards


Core Standards

  • F.TF.A.1 — Understand radian measure of an angle as the length of the arc on the unit circle subtended by the angle.
  • F.TF.A.3 — Use special triangles to determine geometrically the values of sine, cosine, tangent for π/3, π/4 and π/6, and use the unit circle to express the values of sine, cosine, and tangent for π-x, π+x, and 2π-x in terms of their values for x, where x is any real number.

Foundational Standards

  • G.C.B.5

Criteria for Success


  1. Visualize transformations of sine, cosine, and tangent on the unit circle.
  2. Use transformations of sine, cosine, and tangent to more quickly evaluate particular angles. 
Fishtank Plus

Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.

Anchor Problems

25-30 minutes


Problem 1

FInd the value of the expression below:

$${\mathrm{sin}\frac{11\pi}{6}}$$

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

References

EngageNY Mathematics Precalculus and Advanced Topics > Module 4 > Topic A > Lesson 1Lesson 1, Exercise 2

Precalculus and Advanced Topics > Module 4 > Topic A > Lesson 1 of the New York State Common Core Mathematics Curriculum from EngageNY and Great Minds. © 2015 Great Minds. Licensed by EngageNY of the New York State Education Department under the CC BY-NC-SA 3.0 US license. Accessed Dec. 2, 2016, 5:15 p.m..

Problem 2

Explain why each of the following expressions are equivalent:

$${\mathrm{sin}\theta=\mathrm{sin}(x-\theta)}$$

$${\mathrm{cos}\theta=\mathrm{cos}(2\pi-\theta)}$$

$${\mathrm{cos}\theta=\mathrm{cos}(-\theta)}$$

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Target Task

5-10 minutes


Problem 1

Evaluate the following trigonometric expressions and explain how you used the unit circle to determine your answer.

a.   $${\mathrm{sin}\left(\pi+\frac{\pi}{3}\right)}$$

b.   $${\mathrm{cos}\left(2\pi-\frac{\pi}{6}\right)}$$

References

EngageNY Mathematics Precalculus and Advanced Topics > Module 4 > Topic A > Lesson 1Exit Ticket, Question #1

Precalculus and Advanced Topics > Module 4 > Topic A > Lesson 1 of the New York State Common Core Mathematics Curriculum from EngageNY and Great Minds. © 2015 Great Minds. Licensed by EngageNY of the New York State Education Department under the CC BY-NC-SA 3.0 US license. Accessed Dec. 2, 2016, 5:15 p.m..

Problem 2

Corinne says that for any real number $${\theta}$$, $$\mathrm{cos}{\theta}=\mathrm{cos}{\theta}-\pi$$. Is she correct? Explain how you know.

References

EngageNY Mathematics Precalculus and Advanced Topics > Module 4 > Topic A > Lesson 1Exit Ticket, Question #2

Precalculus and Advanced Topics > Module 4 > Topic A > Lesson 1 of the New York State Common Core Mathematics Curriculum from EngageNY and Great Minds. © 2015 Great Minds. Licensed by EngageNY of the New York State Education Department under the CC BY-NC-SA 3.0 US license. Accessed Dec. 2, 2016, 5:15 p.m..

Additional Practice


The following resources include problems and activities aligned to the objective of the lesson that can be used for additional practice or to create your own problem set.

  • Include problems evaluating angles close to $${\pi}$$ and $$2{\pi}$$ and ask students to visualize them multiple ways.
  • Include problems asking about the equivalence of different expressions, as in the second anchor problem.
  • Include problems evaluating expressions written multiple ways and explaining why they are the same, such as $$\mathrm{cos}\frac{3{\pi}}{4}$$ and $$\mathrm{cos}\frac{5{\pi}}{4}$$.

Next

Graph transformations of sine and cosine functions (Part I).

Lesson 9
icon/arrow/right/large

Lesson Map

A7CB09C2-D12F-4F55-80DB-37298FF0A765

Topic A: Trigonometric Ratios in Application and on the Unit Circle

Topic B: Graphing Sine, Cosine, and Target

Request a Demo

See all of the features of Fishtank in action and begin the conversation about adoption.

Learn more about Fishtank Learning School Adoption.

Contact Information

School Information

What courses are you interested in?

ELA

Math

Are you interested in onboarding professional learning for your teachers and instructional leaders?

Yes

No

Any other information you would like to provide about your school?

We Handle Materials So You Can Focus on Students

We Handle Materials So You Can Focus on Students

We've got you covered with rigorous, relevant, and adaptable math lesson plans for free