896]
which is
A TRANSFORMATION IN ELLIPTIC FUNCTIONS.
V v (A)
and similarly the whole coefficient of dx 2 is
1
(- x 2 ) [D s/(A) + B VC#)};
x 3 v(4)
Hence the terms in dx x , dx 2 are together
OO № ^{A) + b^(E)}.
1 (x x dx 2 - x 2 dx x ) —) + B V W .
X 3
V(H) '~ m/ x 3
and since the terms in dy X) dy 2 are of the like form, we have
dz = j—^ (Xidxa - x 2 dxj) + (y x dy 2 - y 2 dy x )\ x D + E
and combining herewith the foregoing value
V(4^ 3 — Iz - J) =
we have the required formula
D^(A) + E^(B)
A 3
dz
x x dx 2 - x 2 dx x y x dy 2 - y 2 dy x \
VCB) }
\J(4>z 3 — Iz — J) ( *J(A)
As a very simple verification, suppose a = l, b=c = d = e = 0; then
(A, B, C, D, E)=(xA x x %, x I 2 y{\ x x y x 3 , y x %
and if A — x x y 2 — x 2 y x as before, then
rr> %/jj 2
z _ Xl V 1 = 0 2
(x x y 2 - x 2 y x f
where
a — ~ 1 _ _ V±
^i2/2 - x 2Vi V 2/l
Also / = 0, J=0, and consequently
dz _ dz _d6 _ x x dx 2 — ic 2 f^i V\dy 2 — y 2 dy x
V(42 s — Iz — J) 2 V(^ 3 ) # 2 ^i 2 yi 2
which, in virtue of the foregoing values of A, E, is
x x dx 2 - x 2 dx x y x dy 2 — y 2 dy x
V(A)
V(^)
31
I remark that an even more simple transformation from the general quartic
radical to the Weierstrassian cubic radical was obtained by Hermite; this is alluded