= 2n2 (E − z) (1 − z2) − (G′ − Gz)2 /A2 = 2n2 (D − z) (1 − z2) − (G − G′z)2 /A2 = 2n2 Z suppose.

Denoting the roots of Z = 0 by z1, z2, z3, we shall have them arranged in the order

z1 > 1 > z2 > z > z3 > −1.

(14)

(dz/dt)2 = 2n2 (z1 − z) (z2 − z) (z − z3).

(15)

nt = ∫ zz3 dz/ √(2Z),

(16)

an elliptic integral of the first kind, which with

m = n √ z1 − z3, κ2 = z2 − z3,
2 z1 − z2