The excercise is in the attached file, I've solved it but I'm not sure my solution is correct. I hope you'll be able to tell me if my solution is correct or any other usefull comments.

It's mostly in hebreW but I think it's possible to understand Without translating the Whole thing.

the excercise reads as folloWs: "Solve the PDE so that the coeffitions of U(x,y) are less than n^(-2)"

f1, f2, and f3 are C1 (that's a given).