How to Calculate the Virial Theorem for a Particle Moving in a Potential?

Denver Dang
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Homework Statement


A particle is moving along the x-axis in the potential:

\[V\left( x \right)=k{{x}^{n}},\]
where k is a constant, and n is a positive even integer. \left| \psi \right\rangle is described as a normed eigenfunction for the Hamiltonoperator with eigenvalue E.

Show through the "Virial Theorem" that:

\[\begin{align}<br /> &amp; \left\langle \psi \right|\hat{V}\left| \psi \right\rangle =\frac{2}{n+2}E \\ <br /> &amp; \left\langle \psi \right|\hat{T}\left| \psi \right\rangle =\frac{2}{n+2}E, <br /> \end{align}\]<br />
where \hat{V}\ and \hat{T}\ denotes the operators respectively for potential and kinetic energy.

Homework Equations


The Virial Theorem:

\[2\left\langle T \right\rangle =\left\langle x\frac{dV}{dx} \right\rangle \]

The Attempt at a Solution


Well, I'm kinda lost.
I'm not sure how to calculate anything tbh...

The thing that confuses me, which is what I think I should do, is calculating:

\[\begin{align}<br /> &amp; \left\langle \psi \right|\hat{V}\left| \psi \right\rangle \\ <br /> &amp; \left\langle \psi \right|\hat{T}\left| \psi \right\rangle \\ <br /> \end{align}\]<br />

But can't find anything in my book that shows how to calculate anything that looks like that.

So a hint would be very helpful :)Regards
 
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Start with

<br /> \left\langle \psi \right|\hat{H}\left| \psi \right\rangle = \left\langle \psi \right|\hat{T} + \hat{V} \left| \psi \right\rangle.<br />

What is the left side? What is the right side?
 
Sorry for the late reply...

But that is my problem. I'm not sure how to calculate that ?
Is it an integral, a commutator trick, or...? As I said, I can't seem to find anything in my book that shows how to calculate that.
 
Start at the beginning. What is

\left\langle \psi \right|\hat{H}\left| \psi \right\rangle?
 
Hint to George Jones' question:

\left| \psi \right\rangle is described as a normed eigenfunction for the Hamiltonoperator with eigenvalue E.
 
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