when laser light of wavelenght 633.8nm passes through a diffraction grating, the first bright spot occurs at +- 18.6 degrees from the central maximum.
Part A: What is the line density (in lines/cm) of this grating?
Part B: How many additional pares of bright spots are there beyond the first bright spot?
Part C: At what angles do the second bright spots occur?
Part D: At what angles do the third bright spots occur?