3. A) If a window (n1 = 1.5) is coated with another material (n2 > n1), derive expressions for thickness that give maximum reflection and minimum reflection. Note that light undergoes a phase change of 180 degrees upon reflection when incident on a medium of higher refractive index but no phase change upon reflection when incident on a medium of lower refractive index. B) If you are designing a car window with the thin film coating material of n2 to minimize reflection of the sunlight, determine the optimum thickness you would choose. Assume the window is tilted 45 degrees with respect to the ground. Justify your answer given the hypothetical coating material has a refractive index with the following wavelength dependence. n2(2) 1.1 +0.00125 for spectral range of relevance with in nm.