3) Use a light (with wavelength 450 nm in vacuum) and nx=2.6. For part (b), To generate the plot you will need to write a Matlab routine to calculate the reflectivity for vacuum wavelengths starting from 250 nm to 700 nm. Attach your routine along with your plot to your project report. Material A (refractive index: 2.5), Material B (refractive index: 2.1) and Material C (refractive index: 1.75). For part (d), To generate the plot you will need to write a Matlab routine to calculate the reflectivity for vacuum wavelengths starting from 250 nm to 700 nm.