190 THE ROYAL SOCIETY OF CANADA 
then will 
ne; — le; 
ind B” = = ind Pp’ 
N — 

les — Mes o 
= ——— = ind Q’ 
Hence if 
FA D. DS Aer + W16 + 1163 
A++ 
then will 
(M — Det me +716 
À + +r — 1 
Me + (ua — M) 6 + 7163 
M+ a+ — 
Me + me + (11 — n) SES 1 
Art eat — 
And D;=EO . FP 
; ind D; ind F ind P=0 
[= (A — Dé + uét+ve} EH De tpetne 5 
Sn nr du Atm+n—l 
{Xe +(u— metre) {Met (ui — 112) e+ r16 | =0 
x(A—L) wf (x) Qi-)) xe i (1—x) m1 caer (1—x)n |= 
ind O = 
ince — 
ind Q = 
o—l o;—l o—l o,—l- ol 1 —L 
À : u—m y 
M mm Vj 
in which o-=\A-+yu-+» and fe A+ tr 
Solving for x gives 
o—l 
x= 

o— 01 
_ A=AM)at(u—mety—n)es 
Nar hs SP i Mi— Vi 
ae (A+u+y) ind D,— (Qit+ui+n) ind D: 
NÉE 
ind D; = 
*. D,, D: and D; are collinear. 
