Hello everybody, I'm new to this forum and I have some difficulties / worries about this second order non linear differential equation. I posted this problem on physicshelpforum.com (original post here), but I would like to know from you whether this differential equation is solved properly or not. This is what I got:

http://img.photobucket.com/albums/v4...a/P2190001.jpg
http://img.photobucket.com/albums/v4...a/P2190002.jpg

The equation I need to solve is marked (1). Thanks in advance.