An expanded beam of red light from a HeNe laser ( 0 = 632.8 nm) is incident

An expanded beam of red light from a He–Ne laser (λ₀ = 632.8 nm) is incident on a screen containing two very narrow horizontal slits separated by 0.200 mm. A fringe pattern appears on a white screen held 1.00 m away.

(a) How far (in radians and millimeters) above and below the central axis are the first zeros of irradiance?

(b) How far (in mm) from the axis is the fifth bright band?

(c) Compare these two results.