Changes

<math>\Psi _{Mirror} = \Psi _3 = A \sin ( \omega t) </math>

<math>\Psi _{Mirror} = \Psi _3 = A \sin ( \omega t) </math>

(For simplicity, we will say that the wave leaving the mirror has not been phase-shifted.)

(For simplicity, we will say that the wave leaving the mirror has not been phase-shifted, and we will select constants <math>C _1 </math> and <math> C _2 </math> such that <math> C _3 </math> becomes 1, as above.)

Because all three waves are reflections of the same original wave, they all have the same amplitude and frequency.

Because all three waves are reflections of the same original wave, they all have the same amplitude and frequency.