restart;
variables := s, phi(s);
                           s, phi(s)
expr := (k*s^2+1)*(diff(phi(s), s, s))-k*phi(s)+s*k*(diff(phi(s), s));
  /   2    \ / d  / d        \\                  / d        \
  \k s  + 1/ |--- |--- phi(s)|| - k phi(s) + s k |--- phi(s)|
             \ ds \ ds       //                  \ ds       /
expr2 := int(expr, s);
                           /   2    \ / d        \
             -s k phi(s) + \k s  + 1/ |--- phi(s)|
                                      \ ds       /
int(expr2, s);
            /              /   2    \ / d        \   \
         int|-s k phi(s) + \k s  + 1/ |--- phi(s)|, s|
            \                         \ ds       /   /

solve({int(expr2, s)});
Error, (in solve) cannot solve expressions with int(-s*k*phi(s)+(k*s^2+1)*(diff(phi(s), s)), s) for s

I DIDN'T GET THE SOLUTION.PLEASE HELP
 

 how can i define constants alpha and beta are positive in maple? ;these constants are coefficints of PDE (higgs field equation)

restart; with(PDEtools);
U := diff_table(Psi(`ψ_2`, `ψ_1`));
pde := `ψ_2`*(diff(Psi(`ψ_2`, `ψ_1`), `ψ_1`))+`ψ_1`*U[`ψ_1`]+2*U[] = 0;
ψ_2 Psi(ψ_2 + 1, ψ_1)

   + ψ_1 Psi(ψ_2 + 1, ψ_1) + 2 Psi(ψ_2, ψ_1) = 

  0
pdsolve(pde);
Error, (in pdsolve/info) first argument is not a differential equation

How can i solve it?

how do i solve a system of PDE's with variable coeffiecients in Maple?