1. The problem statement, all variables and given/known data Hi there, i am trying to do a proof that H'(t)= δ(t) 2. Relevant equations We have been given the following: F is a smooth function such that lim (t-->±∞)F(t)=0 Therefore the integral between ±∞ of [H(t)F(t)]'=[H(t)F(t)]∞-∞=0 I understand it up until this point; however next it says: "Integration by parts: (1) = Integral between ±∞ of [H(f)'F(t)]dt (2) = -the integral between ±∞ of H(t)F'(t)dt (3) = -the integral between ∞ and 0 of F'(t)dt (4) = [-F(t)]∞0 (5) = F(0) (6) = Integral between ±∞ of δ(t)F(t)dt 3. The attempt at a solution I dont know where they have got theequation from in (1) or (2) or (3)! I get 4 though and 5! Although i dont then get 6! I think if i knew where (1) came from i maybe could get through the rest but i just dont know where it has come from?