1. The problem statement, all variables and given/known data Hi guys Please take a look at the second question in 10.20 (the question with the diff. equation): http://books.google.com/books?id=Mq...ts=JOvnmWE-Jo&sig=FP2sASpndHBj_ETidnKSzSxsFd4 I have found the expression for the operator E, but how do I show that f(r) satiesfies the diff. equation? 3. The attempt at a solution First thing would be to insert "psi"(r,theta) in E - but where to go from here? I am very lost. Thanks in advance, sincerely Niles.