\ 
[ 571 ] 
VII. 
Subftituting in the equations — iy z* + 1 = o, 
and z 1 — 2 x z 1 — o, a - ^ M inftead of z, we have 
Cl — CO 
a -f- 
co 
a—— co 
zn 
zn 
— 2 y x 
# + 
CO 
Cl O) 
+ I 
in. 
a~Y co — 2yxa~j~coxa — « -j- a 
CO 
zn 
= o, and 
a — co 
a -+- 
ca 
a — co 
z 
# “f- <0 , 
2 X X + I 
Cl co 
ci co — 2 x x a -f- co x a 
CO 
+ a 
CO 
Cl CO 
2 + 2 X X co % + 
X 
a * 
1 -f- x __ 
o. Confequently 
ci CO 
zn 
a -j- co — 2 y x a -j- co xa — w -j" a — w whl be =? 
j p 
2 -j -2pX2~\-2.qx2.-\- 2 r y See. x co z -f- - — — a- 
Tp 
X CO* 1 
I q 
a? x co z + - — ; — cf, See. 
I ~p r 
But, bysirt.YV. 2 -j- 2 x 2 2 q x 2 2 r, Sec. 
is = 2 + 2 y, the upper or lower of the two figns 
4 C 2 prefix’d 
