1. The problem statement, all variables and given/known data A particle of unit mass moving in an infinite square well, V=0 for |x|<= a , V=∞ for |x|>a , is described by a wave function u(x) = Asin(3πx/a). (i) If I normalise the wave function, what is A? (ii) And what is the energy of state described by this wave function? 3. The attempt at a solution (i) Normalised the wave function by saying it is only valid from 0<x<=a and every where else is 0. So I square the wave function, integrate it and I get: A²a = 1 --> 1/√a (ii) And the energy of state decribed by this wave function would be 9h²/8ma² , since we know its on n=3. What Im puzzled about is if the width of the well is 2a or a? I know it is 'a' because the denominator of the wave function tells me it is. But when I use the general formula of: A= √(2/L) I know L = a so I instead get: A= √(2/a) which isn't true? Thanks.