(16)

∞ > u = aeπs/c > a,

(17)

and this gives the intrinsic equation of the jet, and then the radius of curvature

ρ = − ds= 1 = i dw= i dw/
Q Q Qdu du
= c· u − b √ (u − a·u − a′),
π u√ (a − b·b − a′)

(18)

not requiring the integration of (11) and (12)

If θ = α across the end JJ′ of the jet, where u = ∞, q = Q,

ch nΩ = cos nα = √ b − a′, sh nΩ = i sin nα= i √ a − b,
a − a′ a − a′