In[]:=
ClearAll["Global`*"]
In[]:=
u[Φ_]:=1+Csch[x]+Tanh[x]​​β:=1​​k:=1​​α:=1​​κ0:=1​​c:=1​​s:=1​​a:=1​​b:=1​​r:=1​​ω:=ak+br+cs+
1
96
(8
3
k
β+9kακ0(16+5ακ0))​​f[Φ_]:=ak+br+cs-ω+
15
32
k
2
α
2
u[x]
D[u[x],x]+
1
6
3
k
βD[u[x],{x,3}]/.xΦ
​​
In[]:=
Plot[f[Φ],{Φ,0,30}]
Out[]=