A sheet of glass (nglass = 1.5) is coated with a 95.6-nm-thick layer of magnesium fluoride (ncoating = 1.38) to prevent reflection in the visible spectrum. Assume the incoming light is normal to the surface.
What is the longest wavelength of light strongly reflected from this coated surface?
The Attempt at a Solution
95.6 = x/4(1.38) = 527 nm
This is incorrect however.