Introduction to Sine and Cosine Functions

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Unit 2 - Circular Functions

(3) Intro Sine and Cosine

Introduction to Sine and Cosine Functions

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Unit 2 - Circular Functions

(3) Intro Sine and Cosine

Graphic Sinusoid

the graph of any trigonometric function.

Verbal: Related Vocabulary Periodic function is a function whose values repeat at regular intervals.

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Unit 2 - Circular Functions

(3) Intro Sine and Cosine

Cycle the part of the graph from any one point to the point where the graph starts to repeat.

Period is the difference between the horizontal coordinates corresponding to one cycle. (How long does it take the function to start repeating.)

The parent function, the function without any transformations, of sine and cosine has a period of 360 degrees.

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Unit 2 - Circular Functions

(3) Intro Sine and Cosine

Algebraic The function f is a periodic function if and only if there is a number p for which f(x-p)=f(p)

Numeric Do not copy. Follow the directions to create a drawing. 1. Draw a first quadrant angle in standard position. Label the terminal side r. 2. Label the initial side x. 3. Draw a line from the terminal side to the horizontal axis. Label that line y. That is called a reference triangle.

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Unit 2 - Circular Functions

(3) Intro Sine and Cosine

Using that triangle write the value of

and

How do they relate to what you already know about those function?

Definitions

SOH-CAH-TOA 5

Unit 2 - Circular Functions

(3) Intro Sine and Cosine

Now let's take a look at the drawing and discuss what is happening to the graph and how it relates to the coordinate plane.

QUADRANT II

SINE

TANGENT QUADRANT III

QUADRANT I

ALL

COSINE QUADRANT IV

ALL STUDENTS TAKE CHEMISTRY 6

Unit 2 - Circular Functions

(3) Intro Sine and Cosine

Problems The terminal side of an angle in standard position contains the point (-3,4). Sketch the angle in standard position and find the sine, cosine and tangent of the angle.

The terminal side of an angle in standard position contains the point (8,-6). Sketch the angle in standard position and find the sine, cosine and tangent of the angle.

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Unit 2 - Circular Functions

(3) Intro Sine and Cosine

The terminal side of an angle in standard position contains the point (-3,-7). Sketch the angle in standard position and find the sine, cosine and tangent of the angle.

The terminal side of an angle in standard position contains the point (-1,-5). Sketch the angle in standard position and find the sine, cosine and tangent of the angle.

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Unit 2 - Circular Functions

(3) Intro Sine and Cosine

What is the sine of theta if theta equals 180 degrees? Prove it! The calculator told me is not proof!!!!

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