Post on 26-Mar-2015
9.2 FUNDAMENTAL TRIGONOMETRIC IDENTITIES AND USING A CALCULATOR
THE TRIGONOMETRIC FUNCTIONS
Osin
H
Acos
H
Otan
A
Hcsc
O
Hsec
A
Acot
O
SOHCAHTOA
THE RECIPROCAL IDENTITIES
1sin
csc
1cos
sec
1tan
cot
1csc
sin
1sec
cos
1cot
tan
THE QUOTIENT IDENTITIES
sintan
cos
cos
cotsin
USE THE GIVEN INFORMATION TO FIND THE VALUE OF EACH OF THE FOUR REMAINING TRIGONOMETRIC FUNCTIONS.
2sin
5 21
cos5
USE THE GIVEN INFORMATION TO FIND THE VALUE OF EACH OF THE FOUR REMAINING TRIGONOMETRIC FUNCTIONS.
2sin
3 5
cos3
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
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
USE A CALCULATOR TO FIND THE VALUE TO FOUR DECIMAL PLACES.
Scientific Calculator
Graphing
Calculator
sin30
30 cos cos 30 enter
USE A CALCULATOR TO FIND THE VALUE TO FOUR DECIMAL PLACES.
Scientific Calculator
Graphing
Calculator
cot 45
45 tan 1 x 1tan 45 x
USE A CALCULATOR TO FIND THE VALUE OF THE SIX TRIGONOMETRIC FUNCTIONS FOR THE GIVEN ANGLE TO FOUR DECIMAL PLACES.
25
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
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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