f[r_]:=1-
2M
2
r
3
r
+
3
g
+
8
3
πP
2
r
;​​T=
1
6
r8P+
3M(-2
3
g
+
3
r
)
π
2
(
3
g
+
3
r
)
;​​ξ=
3
(3+8π
2
r
)
3
(
3
g
+
3
r
)
216
6
r
+
6
g
-
3
g
3
(3+8π
2
r
)
3
(
3
g
+
3
r
)
108
6
r
-
3
g
;​​rp=
3
g
2
2
r
+
r
2
+
4
3
(
3
g
+
3
r
)Pπ+
2
(3+8π
2
r
)
2
(
3
g
+
3
r
)
36
4
r
1
3
ξ
+
1
3
ξ
;​​rs=
rp
f[rp]
;