Exceptation of energy by Hamiltonian

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SUMMARY

The Hamiltonian for the harmonic oscillator is defined as H=0.5*[P^2/m + (4*h^2*x^2)/(m*σ^4)], where h represents h-bar. To calculate the expectation value of energy using the wave function ψ(x)=A*exp{-[(x-bi)^2]/σ^2}, the integral ∫ψ*Hψdx must be evaluated. The correct expectation value of energy is derived as (h^2/m)*(1/σ^2 + (2*b^2)/σ^4). A change of variables in the integrals can simplify the calculation process.

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axcelenator
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Hello,

The question says that we can write the Hamiltonian of the harmonic oscilator like this:
H=0.5*[P^2/m + (4*h^2*x^2)/(m*σ^4)] where h is h-bar

I need to calculate the expectation value of energy of the oscilator with the next function: ψ(x)=A*exp{-[(x-bi)^2]/σ^2}.

I tried to the the integral: ∫ψ*Hψdx where H is the operator of p and x but I got a big integral and I don't think its the write way because the finite answer is pretty simple:
Answer: (h^2/m)*(1/σ^2 + (2*b^2)/σ^4) where h is h-bar

How can I solve it?
Thanks
 
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I'm not sure there is a simpler way. Could you show us some of your work?

Also, you could consider a clever change of variables in the integrals (recall that you need to determine the constant A as well).
 

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