[895
or a 4 , we obtain in each
of 24, viz. 6, 4, 1 in the
as, viz. there is 1 tree
thus proved. Hence the
to see that the proof is
896]
29
given knots A, a, /3, y,
nots A,, /x, a, /3, 7, ..., the
a, /3, 7,...) the triads of
A, fi, v always belonging
of the knots A, p, v, ...,
trees or pairs, or triads,
then n being the number
of knots A, a, ¡3, 7, ...,
here i= 1, n — 2, and we
3S are
(A/3, pa).
= 4 x 1.4 2 = 64
+ 6x2.4' 48
+ 4x3.4° 12
+ 1 1
125,
branch a/3 to any tree
+ 7, 8, e); the branches
stly the tree a(3. ay. a8. ae:
.ble manner. The whole
; the theorem is of course
oer by Borchardt, “ Ueber
lations-Resultante,” Crelle,
¡rs a certain determinant,
.., nO, n\, ..., nn— 1, and
anches of the tree being
al to the product of the
is thus =(n+l) }l_1
896.
A TRANSFORMATION IN ELLIPTIC FUNCTIONS.
[From the Quarterly Journal of Pure and Applied Mathematics, vol. xxiv. (1890),
pp. 259—262.]
The formula in question is given in Klein’s Memoir “Ueber hyperelliptische
Sigmafunctionen,” Math. Ann. t. xxvii. (1886), pp. 431—464, see p. 454, in the form
u
- r co (1A - Vf f(y)\+F(x, y)
"kvîTW e( ) ~ 2(*yr ' ■
(the discovery of it being ascribed to Weierstrass) ; and it is also given in Halphen’s
Traité des Fonctions Elliptiques, t. 11. (1888), p. 357.
The algebraic foundation of the theorem is as follows : writing
z = \ [f{ae) + c},
and as usual I, J for the two invariants of the quartic function (a, b, c, d, efx, y) 4 , we
have identically, as is easily verified,
4z z — Iz — J = [d f(a) + b \f(e)Y,
or say
Hence putting
V(40 3 — Iz — J)= d f(a) + b \J(e).
A = (a, b, c, d, e\x 1} îc 2 ) 4 ,
B=(a, ##1, xtf(y it y 2 ),
E=(a, ^y u y 2 ) 4 ;
A = Xi y2 x 2 yi,
as
and