From (7) the result is ( ≈ 2.530... Hc ), that corresponds to a relative error inferior to
4 4 10− × . Thus the precision for both extreme approximations (ν = 1) and (ν = ∞) and
hence for any value of (ν ) as given by (7) is at least 0.6 %. This is evidently sufficient for
most practical applications taking into account the simplicity of the formula (7) and the
continuity from (ν = 1) to (ν = ∞) for all intermediate values of (ν ), both integral and
fractional.