jMG,
thank you for your comment.
Tom,
I am not sure what you mean by "y1 is wrong".
Certianly it is an approximation ,which I said, and the fact I have found it using the two scale method means that the approximation is "valid" for "small" eps.
Also the y2 you found is quite close to y1.
Could you please clarify?
Thank you
Best Regards
Marco