t
2
8
°
T
(
θ
)
S
(
θ
)
=
s
i
n
(
θ
)
(
1
-
c
o
s
(
θ
)
)
2
1
∫
c
o
s
(
θ
)
1
-
2
x
x
=
0
.
7
4
0
4
2
5