1. The problem statement, all variables and given/known data A grating having 1000 lines per mm is illuminated with sodium light of mean wavelength 589.3 nm. Determine the maximum order of diffraction that can be observed. 2. Relevant equations dsin([tex]\theta[/tex])=m[tex]\lambda[/tex] d=slit spacing 3. The attempt at a solution The order of diffraction is given by m, and m=(dsin[tex]\theta[/tex])/[tex]\lambda[/tex], so i figure m takes a maximum value when sin([tex]\theta[/tex])=1, or when m=d/[tex]\lambda[/tex] but i am not sure if this is correct. I'd be grateful for any hints.