I'm having trouble understanding what David Griffith did in equation [1.25]. In this section he's trying to prove that psi stays normalized and I'm following him from [1.21] to [1.25] and where I'm getting stuck is understanding how: ∂/∂t|ψ|^2= i[itex]\hbar[/itex]/2m(ψ*∂²/∂x²[ψ]-∂²/∂x²[ψ*]ψ) [1.25] He makes this equal to yet another confusing equation, but I think if just understood what substitution he made then I'd be able to progress. (This is independent study so I have no university professor to ask). Also, I'm assuming someone has the book to look at what the confusion is. If someone wants to help but doesn't have the book, I'm willing to write out steps 1.21 to 1.25.