I
n
[
]
:
=
S
o
l
v
e
[
6
C
o
s
[
2
x
]
0
,
x
]
O
u
t
[
]
=
x
1
2
-
π
2
+
2
π
1
i
f
1
∈
,
x
1
2
π
2
+
2
π
1
i
f
1
∈
W
h
a
t
i
t
s
h
o
u
l
d
b
e
:
x
1
2
-
π
2
+
π
1
i
f
1
∈
,
x
1
2
π
2
+
π
1
i
f
1
∈