\ 



348 MEMOIRE RL'a I.\ DISTRIBUTION DK l'eLECTRICITE ETC. 



(<82) /(^^•) = 



ah 



•■("i'Y 



k 



a 



^"^ P\,^^a{a — cx) P,,)—o,{ab)''A-a(a — (x)7.,iP\,^ 



-»-7v 



:L\{abY 



a', {a by 



P ,^— 2\((tby-+-{a — cx)2uP\,) 



'(a by 



^^P',,-^-u(u-rx)\2P^^,-{2aby\ 

 2Haby 



-Hetc. 



-sf^' 



c'ub — bax(c — ax)P\,) — ab' 



X 



\ab 



'{c — ax)\P,^.—2{ab)^\ — 2ab^xP^,, 



{2aby 



'{c — ax)P\,-, — ab'x\2P^,^^{2ah)-\ 



{2aby 



' {c — ax)\ P(„ — 2' {a by\—2a b' x P\,-^ 



{2abY 



■^{c-ax)P\,,-ab'x\2P^,,^{2abY\ 



(2abf 



'*' {c—ax)\ P(,,)—2'{ab)'' \—2ab'xP\;^ 



-l-ctc. : 



oil Ton a 



