p
o
l
a
r
c
u
r
v
e
l
i
m
a
ç
o
n
:
r
=
a
+
b
c
o
s
(
θ
)
a
1
b
1
θ
0
.
7
8
n
1
k
1
m
1
d
1
α
0
.
7
8