Question: integration -- root of

Dear all

I tried to intgrate this problem

P:=(b8*Omega^8+b6*Omega^6)/(a10*Omega^10+a8*Omega^8+a6*Omega^6+a4*Omega^4+a2*Omega^2+a0);

using these limits

Omega_r1:=beta*Omega_c;
Omega_r2:=(2-beta)*Omega_c;

assume((2-2*beta)*Omega_c>0);
assume(a0>0,a2>0,a4>0,a6>0,a8>0,a10>0,b6>0,b8>0,beta>0);
P_I:=evalf(int(P,Omega=Omega_r1..Omega_r2)):

but the results was not useful I got (RootOf)

              /Sum(
              |    
              |    
-0.5000000000 |    
              |    
              |    
              \    

        5 /     2     \                          ,            /    
      _R  \b8 _R  + b6/ ln(beta Omega_c - _R)      _R = RootOf\a10
  -----------------------------------------------                  
          8          6          4          2                       
  5 a10 _R  + 4 a8 _R  + 3 a6 _R  + 2 a4 _R  + a2                  

    10        8        6        4        2     \ .. )\     Sum(
  _Z   + a8 _Z  + a6 _Z  + a4 _Z  + a2 _Z  + a0/     |         
                                                     |   1     
                                                     | + -     
                                                     |   2     
                                                     |         
                                                     /         

    5 /     2     \                                  ,      
  _R  \b8 _R  + b6/ ln(2 Omega_c - beta Omega_c - _R)  _R =
  ---------------------------------------------------       
            8          6          4          2              
    5 a10 _R  + 4 a8 _R  + 3 a6 _R  + 2 a4 _R  + a2         

        /      10        8        6        4        2     \ .. )
  RootOf\a10 _Z   + a8 _Z  + a6 _Z  + a4 _Z  + a2 _Z  + a0/     

please if you have any idea please help me

regards

Saad