Bogdan L. answered 04/25/20
Effective teacher, researcher - Top 10% Wyzant Tutor in 2020
The condition for a minimum due to a single slit is:
a sinθ = mλ, in which:
a is the width of the slit;
θ is the angle between the shortest line from the center of the slit to the screen (i.e., perpendicular to both) and the line from the center of the slit to the center of the minimum;
m is the minimum order (1, 2, 3, ...);
λ is the wavelength of light.
In this problem, m = 1, therefore
sinθ = λ/a = (565 x 10-9 m)/(0.00600 x 10-3 m) = 0.0942 → θ = 5.40o.