Expectation value of a combination of operators

[dyn]

Homework Statement

I will denote operators by capital letters. The question is calculate

<p | XXPP | x> / <p | x >

Homework Equations

X |x> = x |x> P |p> = p |p> P |x> = -i(hbar)d/dx X |p> = i(hbar)d/dp

The Attempt at a Solution

If I start on the RHS and take PP out I get -(hbar)^2 d^2/dx^2 outside the bracket then I can take the XX outside if it operates on the |x> as x^2 but to be honest I'm not getting anywhere

 

[QuasiParticle]

Use the canonical commutation relation between the operators X and P. With that you can reverse the order of the operators in the expectation value.

 

[dyn]

Thanks. I finally got the answer.