1. The problem statement, all variables and given/known data We are ask to find the probability density of psi(x,t). I know that psi have an exp term but i don't understand how by squaring psi make the exp term disappear. 2. Relevant equations Psi = sqrt(2/L)sin(n*pi*x / L)e^(-2*pi* i(E/h)t 3. The attempt at a solution I attempted changing the exp term into polar coord but I cant seem to get anywhere with that.