8­4 Sine and Cosine Ratios 2011

1

February 09, 2011

Feb 2­12:06 PM

8-4 Sine and Cosine RatiosObj: Use sine and cosine ratios to find missing side lengths and angles

in right triangles.

8­4 Sine and Cosine Ratios 2011

2

February 09, 2011

Feb 2­2:18 PM

1.Write the tangent ratios for A and B

2. Find the value of: the side opposite Bhypotenuse

Warm-Up

3. Find the value of x. Round to the nearest tenth.

8­4 Sine and Cosine Ratios 2011

3

February 09, 2011

Feb 2­2:32 PM

Remember this...?

tan(A)Opposite

Adjacent

AOpposite

Adjacenttan-1 ( )

Today we will look at other ratios found in triangles

8­4 Sine and Cosine Ratios 2011

4

February 09, 2011

Feb 2­2:32 PM

(AOpposite

Hypotenusesin-1 )

The Sine Ratio

8­4 Sine and Cosine Ratios 2011

5

February 09, 2011

Feb 2­2:32 PM

(AAdjacent

Hypotenusecos-1 )

The Cosine Ratio

8­4 Sine and Cosine Ratios 2011

6

February 09, 2011

Feb 2­2:36 PM

These are our three trig ratios.

In Greek, it literally means

"triangle measurement".

8­4 Sine and Cosine Ratios 2011

7

February 09, 2011

Feb 2­3:40 PM

How are we going to remember these?

SOH

CAH

TOA

8­4 Sine and Cosine Ratios 2011

8

February 09, 2011

Mar 5­11:25 AM

Find the value of y:

23

y

300

Step 1: Which trig. ratio should you use?

Step 2: Set up a ratio.

Step 3: Solve.

8­4 Sine and Cosine Ratios 2011

9

February 09, 2011

Mar 5­11:31 AM

Find the value of x:

6   3

12X

0

Step 1: Which trig. ratio should you use?

Step 2: Set up a ratio.

Step 3: Solve.

8­4 Sine and Cosine Ratios 2011

10

February 09, 2011

Feb 27­11:38 AM

Find the sine and cosine ratio of each angle.

sin(T) =

cos(T) =

sin(G) =

cos(G) =

8­4 Sine and Cosine Ratios 2011

11

February 09, 2011

Feb 2­3:01 PM

pg. 441 #1-9, 11-17 odd, 26, 41-43

Homework