Hi, I've got  a worksheet to do for my homework. I answered the first question, and then an error message appeared in the part of the code written by the teacher. At the following part,

Normalisation and expectation values of the superposition state
Lets consider the normalisation of, say, the mixed state Psi represented by the superposition of 1st and 2nd levels at an arbitrary time t.
int(evalc(conjugate(Psi(1,x,t))*Psi(1,x,t)),x=-infinity..infinity);