414]
ON POLYZOMAL CUPVES.
565
YII. If we have
1 ,
1,1,
1
= 0, and (
1 ,
1 ,
1,1)
a ,
b , c ,
d
a
b ,
c , d
a 2 ,
b 2 , c 2 ,
d 2
a 2 ,
b\
c 2 , d 2
a" 2 ,
b" 2 , c" 2 ,
d" 2
b" 2 ,
c" 2 , d" 2
and thence
the tetrazomal has a branch ideally containing (z 3 = 0) the line infinity 3 times; order
is = 5; orders of the trizomals are 3, 2. We have here
VZ : Vm : fn : Vp = a : b : c : d,
VZ^ = a + d , V^=a + d ,
V?^ = b Vm 2 = b 4-
/— /bed /— /bed
A =c +A / a , =c-/ V / —.
VZ] + Vm! + V% 1 = 0, \A 4-Vm 2 + V/i 2 = 0.
a*fli + b Vwj H-cVwi = a (a + d) +Z>b + cc
= ( a -d)d-(6-c) / / b “-
= d|(a-d)-(6-c)^/^|,
which give
Moreover
and similarly
whence in virtue of
fL 4- b Vm 2 4- c = d j(a — d) 4- (6 — c)
ad _ (b — cf
be (d - a) 2 ’
one of the two expressions is = 0; and the trizomals are thus a conic and a cubic.
Article No. 206. The Decomposable Carve; Transformation to a different set of
Concyclic Foci.
206. Consider the decomposable case of
VZ2( + Vra33 4- V?i(S 4- = 0 ;
^ . . . - . I m n p _
viz., the points A, B, C, D lie here in a circle, and we have -+^ + - + ^ — 0.
Taking (A lt A) the antipoints of (A, D); (BA) the antipoints of (B, C)\ then