1. The problem statement, all variables and given/known data This is a question I had in my Quantum Mechanics class but my problem is with the calculus which is why i am posting it here. The question is to find the expectation value of x given the wave function equals Ax^3 where 0 ≤ x ≤ a, 0 otherwise. The solution given in class is 7/8 and I have NO idea how to get that. I am sure my integration is correct but not sure where to go from there. 2. Relevant equations <x>=<ψ| x ψ> 3. The attempt at a solution ∫ψ*xψ dx ∫x(-Ax^3)(Ax^3)dx -A^2∫x^7 dx (-A^2 x^8)/8 from a→0 I know I should know this but i have been out of school a couple of semesters and not doing math. If you tell me which technique to look up that will be fine. Thanks so much!