With the previous problem in mind, return to Eq. (4.19) and take the origin of the coordinate system in the plane-of-incidence and on the interface (Fig. 4.47). Show that that equation is then equivalent to equating the x- components of the various propagation vectors. Show that it is also equivalent to the notion of wavefront continuity.

Fig 4.47

(61't) 9='3 +! ) = 9 =