Behavior at zero and at infinity

[intervoxel]

Hi,

I have a second order DE involving the first derivative and with singularities at zero and at infinity. I need the approximate behavior at zero and at infinity. I have the answer but I would like to know how to get there.

I don't know how to start this search. Any help?

 

[Mute]

For the singularity near x = 0 I would try keeping only the largest terms as x -> 0 and solve the simplified equation.

For the singularity near x = infinity, I would try to change variables to u = 1/x, and then do the same thing around u = 0.

 

[intervoxel]

Bingo! Thanks a lot.