1. The problem statement, all variables and given/known data A beam of yellow laser light (580 nm) passes through a circular aperture of diameter 4 mm. What is the angular width of the central diffraction maximum formed on a screen? (Define the angular width as the full angle from one minimum of the central diffraction maximum to the diametrically opposite minimum.) 2. Relevant equations sinθ=1.22(λ/d) θ = angle to first minimum λ = wavelength d = diameter of aperture 3. The attempt at a solution This problem seems to be fairly straightforward, but I'm not coming up with the correct answer. Convert λ to mm to get .00058, divide by 4, and then multiply by 1.22. This value is equal to sinθ, so simply take sin-1 of that number to get θ. Computer does not like this answer. Help, anyone? Thanks in advance!