it’s for trigonometric functions and right triangles. 4.3 right triangle trigonometry adjacent...
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It’s for TrigonometricFunctions and RightTriangles.
4.3 Right Triangle Trigonometry
θadjacent side
oppositeside
hypotenuseθ−90
Ex. Find the six trig. functions of theta.
θ3
4 h = 5
4
3cot
3
4tan
3
5sec
5
3cos
4
5csc
5
4sin
==
==
==
θθ
θθ
θθ
Quotient Identities
θθθ
θθθ
sin
coscot
cos
sintan
=
=
Pythagorean Identities
θθθθ
θθ
22
22
22
csccot1
sectan1
1cossin
=+
=+
=+
Ex. Use a calculator to evaluate ( )"12'405sec °
First, change the deg, min, sec, to a decimal.
=++3600
12
60
405 °67.5
š
=°67.5cos
167.5sec 1.00492
Note: Make sure your calculator is in degree mode.
Find the height of the tree if a surveyor is 50 ft. from the base of the tree and measures the angle of elevation to the top of the tree as 71.5o.
50’
°5.71
h
505.71tan
h=°
.4.149 fth≈
A 40 ft. flag pole casts a 30 ft. shadow. Find the angle of elevation.
40’
30’
θ
30
40tan =θ
To find , take the INV tan.θ
≈⎟⎠
⎞⎜⎝
⎛−
30
40tan 1 °13.53