I
n
[
]
:
=
v
=
{
2
,
3
,
4
}
;
w
=
{
-
8
,
1
/
2
,
3
/
7
}
;
v
.
w
a
n
g
l
e
=
A
r
c
C
o
s
v
.
w
v
.
v
w
.
w
O
u
t
[
]
=
-
1
7
9
1
4
O
u
t
[
]
=
A
r
c
C
o
s
-
1
7
9
3
6
6
2
4
1