This lecture discusses the correction of the first questions of set 23, focusing on finding an eigenstate of energy E0 in a non-infinite well potential. By considering the Schrodinger equation and a state of the form phi0 of x equals a times exponential minus q of x, the instructor derives the relationship between the energy E0 and the free parameter q, leading to the expression E0 equals v0 minus h bar square to q square over 2m.