At this level, the text book does not give a detail derivation of both the Classical wave equation and the Schrodinger equation but it does provide a solution to these differential equation. My concern at this moment is whether we will be required to know the derivation at this level. Development of Planck's law as well as the Bohr model was much clearly presented in the previous chapter.
One final thought , please briefly touch on the exponential form of the solution ( Euler relation) // complex and imaginary part.
Thanks in advance.