3 Group 17
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Question 1.
If
cos
α
=
-
2
2
,
α
∈
(
0
,
π
)
, then
cos
2
α
is equal to
a)
2
2
b)
0
c)
-
2
2
d)
-
1
e)
1
2
Question 2.
Determine
lim
n
→
∞
3
n
1999
+
2
n
1998
+
n
1997
(
n
1000
+
1
)
2
.
a)
0
b)
3
c)
1
2
d)
2
e)
1
Question 3.
Given functions
f
1
(
x
)
=
cos
(
2
x
)
+
3
4
,
f
2
(
x
)
=
2
x
3
-
5
x
3
,
f
3
(
x
)
=
cos
(
2
x
)
+
3
3
,
f
4
(
x
)
=
2
x
4
+
1
3
,
f
5
(
x
)
=
2
x
3
-
5
x
+
1
3.
From them the following are odd:
a)
f
4
b)
f
5
a
f
1
c)
f
2
d)
f
1
a
f
2
e)
f
1
Question 4.
Calculate
lim
x
→
-
∞
e
x
3
2
x
2
-
1
.
a)
e
b)
1
e
c)
0
d)
1
e)
+
∞
Evaluate