Question

Is the angular position of the first-order spectrum small enough for sinθ≈θ to be a good approximation?.

Answer 1

Answer:

Sin θ = θ     is a useful approximation up to about 10 deg

Sin 10 = .174

10 / 360 * 2 π = .175      where 2 π = 360 deg in a circle (no of radians)