Answer:

Step-by-step explanation:
given
wavelength of light λ = 479 nm
= 479 x 10⁻⁹ m
the angle
θ = 1.15 / 2 = 0.575°
using
condition for diffraction minimum ,
d sinθ = m λ
for first minimum m = 1
d sinθ = λ
therefore ,
slit width

hence, the width of the slit is equal to
