1. The problem statement, all variables and given/known data White light is incident normally on a diffraction grating with slit separation d of 2.00x10^-6m. a)Calculate the angle between the red and violet ends of the first-order spectrum. The visible spectrum has wavelength between 400nm and 700nm. b)Explain why the second and the third order spectra overlap. 2. Relevant equations sinθ=nλ/d 3. The attempt at a solution I was able to solve part (a) by substituting in the above formula with λ=700nm for red and λ=400nm for violet. However I don't really know how to explain (b) I was thinking that for the next spectrum the path difference for red would be 1 complete wavelength so 400+400=800, for violet 700+700=1400. For the third spectrum the path difference would be for red 400+400+400= 1200. So violet from 2nd spectrum seems to be interfering with red from the 3rd spectrum. I know this isn't the correct answer so can someone please help ?