9.2 F UNDAMENTAL T RIGONOMETRIC I DENTITIES AND U SING A C ALCULATOR.

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9.2 FUNDAMENTAL TRIGONOMETRIC IDENTITIES AND USING A CALCULATOR

Transcript of 9.2 F UNDAMENTAL T RIGONOMETRIC I DENTITIES AND U SING A C ALCULATOR.

Page 1: 9.2 F UNDAMENTAL T RIGONOMETRIC I DENTITIES AND U SING A C ALCULATOR.

9.2 FUNDAMENTAL TRIGONOMETRIC IDENTITIES AND USING A CALCULATOR

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THE TRIGONOMETRIC FUNCTIONS

Osin

H

Acos

H

Otan

A

Hcsc

O

Hsec

A

Acot

O

SOHCAHTOA

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THE RECIPROCAL IDENTITIES

1sin

csc

1cos

sec

1tan

cot

1csc

sin

1sec

cos

1cot

tan

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THE QUOTIENT IDENTITIES

sintan

cos

cos

cotsin

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USE THE GIVEN INFORMATION TO FIND THE VALUE OF EACH OF THE FOUR REMAINING TRIGONOMETRIC FUNCTIONS.

2sin

5 21

cos5

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USE THE GIVEN INFORMATION TO FIND THE VALUE OF EACH OF THE FOUR REMAINING TRIGONOMETRIC FUNCTIONS.

2sin

3 5

cos3

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USING A CALCULATOR TO EVALUATE TRIGONOMETRIC FUNCTIONS Remember that when we evaluate

trigonometric functions: the input is the measure of an acute angle and

the output is the ratio of the lengths of the sides

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USING A CALCULATOR TO EVALUATE TRIGONOMETRIC FUNCTIONS For most acute angles, we approximate the

value of each of the trigonometric functions using a calculator.

Look for the keys on your calculator.

To evaluate csc, sec, and cot, we must use the reciprocal identity and/or the reciprocal keys on the calculator.

sin , cos , tan

1 x 1x

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USE A CALCULATOR TO FIND THE VALUE TO FOUR DECIMAL PLACES.

Scientific Calculator

Graphing

Calculator

sin30

30 cos cos 30 enter

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USE A CALCULATOR TO FIND THE VALUE TO FOUR DECIMAL PLACES.

Scientific Calculator

Graphing

Calculator

cot 45

45 tan 1 x 1tan 45 x

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USE A CALCULATOR TO FIND THE VALUE OF THE SIX TRIGONOMETRIC FUNCTIONS FOR THE GIVEN ANGLE TO FOUR DECIMAL PLACES.

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FIND THE MEASURE OF THE SIDE OF THE RIGHT TRIANGLE WHOSE LENGTH IS DESIGNATED BY A LOWERCASE LETTER. ROUND ANSWERS TO THE NEAREST WHOLE NUMBER.

64°

18x

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FIND THE MEASURE OF THE SIDE OF THE RIGHT TRIANGLE WHOSE LENGTH IS DESIGNATED BY A LOWERCASE LETTER. ROUND ANSWERS TO THE NEAREST WHOLE NUMBER.

19°

a

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