I'm trying to practice some operator algebra.. Solve [H,x] where H is the Hamiltonian operator, x is position operator, and assuming one dimensional potential energy, U(x). I know the commutator comes out as -ih_bar(p_op)/m Here is my work so far. [H,x] = Hx - xH note: H = [ -ih_bar(p/2m) + U(x) ] so.. plug it in.. [ -ih_bar(p/2m) + U(x) ] x - x [ -ih_bar(p/2m) + U(x) ] ( x U(x) and -x U(x) cancel) now.. -(ih_bar/2m)(p x) + (ih_bar/2m)(x p) -(ih_bar/2m)[ p x - x p ] x and p are both operators.. so I know they don't cancel.. I'm kind of lost at this point.