College Trigonometry, 2011a

880 Foundations of Trigonometry
85.
(
−π, − π ] (
∪ 0, 3π 4 4
]
86.
[
− 3π 4 , π ]
4
87.
(
−2π, − 3π )
∪
(− 3π ) (
2 2 , −π ∪ 0, π ) ( π
)
∪
2 2 ,π
88. [−2π, 2π]
89. (−2π, arccot(5) − 2π] ∪ (−π, arccot(5) − π] ∪ (0, arccot(5)] ∪ (π, π + arccot(5)]
90.
91.
[
− 7π 4 , − 3π ) (
∪ − 3π 2 2 , − 5π ] [
∪ − 3π 4 4 , − π ) (
∪ − π 2 2 , − π ] [ π
∪
4 4 , π ) ( π
∪
2 2 , 3π ] [ 5π
∪
4 4 , 3π ) ( 3π
∪
2 2 , 7π ]
4
[
−2π, − 5π 3
[
− 11π
92.
6 , −7π 6
93. ( 0, 1 ]
2
] [
∪ −π, − π ] [
∪ 0, π ] [
∪ π, 5π 3 3 3
}
] [ π
∪
6 , 5π 6
] {
∪, − π 2 , 3π 2
]
94. [ 1
2 , 1] 95.
(
−∞,
96. (−∞, ∞) 97. [−1, 0) 98. [ −1, − 1 2
99.
101.
102.
103.
105.
107.
∞⋃
k=−∞
∞⋃
k=−∞
∞⋃
k=−∞
∞⋃
k=−∞
∞⋃
k=−∞
∞⋃
k=−∞
(2kπ, (2k +2)π) 100.
{[ (4k +1)π
,
4
{[ (6k − 1)π
,
3
( kπ
2
( kπ
2
)
(k +1)π
,
2
)
(k +1)π
,
2
[ (4k − 1)π
,
4
) (
(2k +1)π (2k +1)π
∪
,
2
2
] (
(6k +1)π (4k +1)π
∪
,
3
2
]
(4k +1)π
4
∞⋃
k=−∞
(4k +3)π
4
( (4k − 1)π
,
2
]}
)}
(4k +3)π
2
104. (−∞, ∞)
106.
∞⋃
k=−∞
( (2k − 1)π
,
2
√ ]
3
7
) ( √2 ]
∪
2 , 1
)
(4k +3)π
2
)
(2k +1)π
2