541 
infinity and its inflexion asymptote is parallel with the true straight line. 
After this preparatory study we may distinguish the following 
eight cases. 
1. @ right, <2, -toóslows 
KO Ser OGY 8 ay Ss Oh 
d°z 
l 
0, ham (5) nf 
du'* DU en 
dz 
Lim oe = 0, 
du Jute 
iy ak from = oo HOi — tE of 
(fig. 2a). 
(u,2) 
(u‚z) 
2. zo right, «,' too high; 
hen 00 tO or P= 0 F0 
d?z 
dz 
== >0 , Zim — = a 
a 2 ! 
du ONG i as 
dz 
— = Oo 
du’ JC 
uu from u' = —o to v’’=+ C 
(fig. 25). 
B. too low, 2,’ right ; 
begr Oor BOE p=); 
de dz 
— 0 — == oo 
du’? = ; (El, 
: dz 
Lim @ ee 
du ua 
wu >u from wu’ = — B to w= + 0. 
(fig. 2c’. 
4. @ too high, a.’ right; 
ie, 6 > Ot 0 ome 0 ee 
u——@ 
. az 
Lim | — SSA: 
du ) =d 
u <u from u = —o tow = + 0. 
(fig. 2d). 
