In[]:=
ϵ=
∞
∫
1
1
rt

t
t;​​f[r_,P_]:=1-
2M
r
-
2
Q
(
3
r
-
2
r
+2r-6)
r

(6
2
r
)
+
8πP
2
r
3
+
1
6
2
Q
ϵ
2
r
-
c
1+3ω
r
;
In[]:=
Q=0.5;M=2;c=0.1;ω=
-1
3
;
In[]:=
Clear[fPlot];​​fPlot[P_]:=D[f[r,P],r]/(4*Pi)/.Last@NSolve[f[r,P]==0&&r>0,r,Reals];
In[]:=
Plot[fPlot[P],{P,0,0.3},PlotRange->{0,0.5},PlotStyle->Green,​​AxesOrigin->{0,0}]
Out[]=
$Aborted