C H A P T E R 5 Analytic Trigonometry

508 Chapter 5 Analytic Trigonometry
118. cos2 arccos x cos2arccos x sin2arccos x 119.
120. (a)
121.
122.
cos h
2 10
sin 12b
2 10
sin 1
2 M
(a)
(c)
x
2
x 2 1 x 2 2x 2 1
A 1
bh (b)
2
⇒ h 10 cos
2
A 10 sin
10 cos
2 2
sin
1
2
arcsin 1
2
2
2
S
1
760
S 760 miles per hour
S
4.5
760
1
⇒ b 10 sin
2 2
S 3420 miles per hour
1 cos
2r sin2 2r 2
r1 cos
So, x 2r1 cos .
10 m
⇒ A 100 sin cos
2 2
θ
b
h
10 m
(b)
(d)
1
32 752 sin 2 130
sin 1
2 4.5
2
sin 1
2 M
2
2 sinu cosu
2sin u cos u
2 sin u cos u.
sin 2 13032
75 2
1
2 sin1 13032
75
23.85
A 100 sin
cos
2 2
2
(b) A 502 sin cos
2 2
(b) A 50 sin
2, sin 1 ⇒
(b) When
is a maximum.
the area
(b) A 50 sin square feet
501 50
2
arcsin 1
4.5
2 arcsin 1
0.4482
1
arcsinM 2 arcsin 1
2 123. False. For u < 0, 124. False. If 90 < u < 180,
u
sin 2u sin2u
is in the first quadrant and
2
4.5
M
sin u
2
1 cos u
.
2