Expectation Value in Inf. Box in an Eigenstate

1. Dec 15, 2008

EnershyMethod

1. The problem statement, all variables and given/known data
Obtain an expression for the expectation value <Pxn>n N=1,2.... of a particle in an infinite box ( V=$$\infty$$ for x<0 and x>L ; V=0 for 0<X<L) which is in an eigenstate of the energy.

2. Relevant equations
Pn =+- $$\sqrt{2*m*En }$$ = +- (n*pi*Hbar) / L

3. The attempt at a solution
I don't know how to approach the problem because I am not sure what the notation of P is in the question. I included that formula because it is the closest formula I could find.

How can I approach this? Thanks.

2. Dec 15, 2008

EnershyMethod

BUMP,
We need it for tomorrow.