Thank you, but for ode45 I need the 4 equations in the form dydx=... To obtain this, I have to divide by r^2 again and I have the same problem with the singularities
dy(1)=y(2)
r^2*dy(2)= r*y(2)+...
I have to solve the following coupled differential equations
d^2f(r)/dr^2+1/r*df(r)/dr+(2-2*f(r)^2-2*a*g(r)^2-l_1^2/r^2)*f(r)=0
d^2g(r)/dr^2+1/r*dg(r)/dr+(2-2*g(r)^2-2*a*f(r)^2-l_2^2/r^2)*g(r)=0,
where a is the coupling. I think that it is not possible to solve it analytically (even in...