Quantum Mechanics "Expectation" 1. The problem statement, all variables and given/known data 1. Calculate the expectation value [tex]<p_{x}>[/tex] of the momentum of a particle trapped in a one-dimensional box. 2. Find the expectation value <x> of the position of a particle trapped in a box L wide. 2. Relevant equations [tex]\psi _{n}=\sqrt{\frac{2}{L}}sin \frac{n\pi x}{L}[/tex] [tex]<p_{x}>=\int \psi^*p_{x}\psi dx[/tex] [tex]<x>=\int \psi^*x\psi dx[/tex] 3. The attempt at a solution I got confused on choosing the limits for both the problems for integrating them. What's the limits I should chose for both the problems.