1. The problem statement, all variables and given/known data Normalise Ψ(x,0) (use the fact that both ψ1 and ψ2 are stationary states). Will this wave function be normalised at any later time, t > 0? 2. Relevant equations A particle in an infinite square well of width a has as its initial wave function an even mixture of the first two stationary states, Ψ(x, 0) = A(ψ1(x) + ψ2(x)) . 3. The attempt at a solution I get the concept of normalisation I would integrate the square of A(ψ1(x) + ψ2(x)) between 0 and a and equate it to 1. I am confused how to integrate ψ1(x) or ψ2(x). I see that ψ(n)=(2/L)^0.5 sin(π/L)exp−i(n2π2 ̄h)/2mL2)t does the exponential term cancel when I square the complex conjugate? Anyway any help would be deeply appreciated, thanks.