- #1
terp.asessed
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Hello--I am practicing for the upcoming quiz (as part of quantum physics), but have no idea how to solve the sample problem the teacher gave (w/ solution)...
Write out the operator A2 for A = d/dx + x
(Hint: INCLUDE f(x) before carrying out the operations)
so...I tried:
A {df(x)/dx + f(x)} = d/dx{df(x)/dx + f(x)} + df(x)/dx + f(x)
= d2f(x)/dx2 + df(x)/dx + df(x)/dx + f(x)
= d2f(x)/dx2 + 2df(x)/dx + f(x)
...when the solution is A[SUP]2[/SUP] = d2/dx2 + 2xd/dx + 1 + x2
...where did I make mistake? Could someone please point out? Thanks!
Write out the operator A2 for A = d/dx + x
(Hint: INCLUDE f(x) before carrying out the operations)
so...I tried:
A {df(x)/dx + f(x)} = d/dx{df(x)/dx + f(x)} + df(x)/dx + f(x)
= d2f(x)/dx2 + df(x)/dx + df(x)/dx + f(x)
= d2f(x)/dx2 + 2df(x)/dx + f(x)
...when the solution is A[SUP]2[/SUP] = d2/dx2 + 2xd/dx + 1 + x2
...where did I make mistake? Could someone please point out? Thanks!