258 Opdscdla 



U=xf+x('2.ba -x—y~a) +-y(iba—x—:y—ayirt{iha~l*x—by)+uz 

 Sed t^bx -\-hy — a, u—ba — y — bx , z — ba — x—by 



ejectis ope hanim aequalionum f, i< , 2 ab aequalione praece- 

 dead, habebimus ordlnamlo 



Mi= — j2 — x''--\-xy -\-fi.bnx-\-ibay — ib a^ 



— l^ y"^ — i\r2 — xy — ax — ay -^-h^ (^ 



+ b y^-hbx^ — xy+^b-ax-^^b^ay 



— b^xy-^ b^ax -[- b^ay 



— b^x y — b a X — bay 

 + xy — b^ax — b^ ay 

 •^b^xy 



= (^b-i -P)y^^(b-i -b^)x'-h{bi-ib^)xy + {^b2-\-b-i )ax 



est autem l>~=b-{-i , ct ideo 6^=d--^d=z2l>-j-i-, ergo aequa- 

 tio praeccdens reduciuir ad 



}l — —y2(b + ^) — x-{b + ^) — xy(Zb + i)+ay(5b-\-0 

 -f-aa:(36-+-i)+a2(i— i). 



la hac aequatione loco a ponatur , atque loco a^ 5r*, 



2i— 1 



et erk 



M = — rHt + 2)-a;2(&^-2)-a:J(36+l)-H^^Zi^^i-Ii_ 

 a6 — I 



+ J:^iM±il+ 5 ,-2- 5 £ ;•=. 

 26 — 1 



Est autem ( 2A — 1 ) (6+ i ) =2^^+^ — i=2i-t-i ideo- 



7 5b-Jr 1 



que i+i= __Z_, ergo 



20 — 2 

 M = — 72(6 + 2)— x2 (6+ 2)— x/(3i + i) + 5r7(i+i) 

 + 5rx (b-\-i) — bb A-2-I- 5 1'2 

 gtque dividendo per ^-1-2 



M 2_ 2 _■^7(^^'^0 1 •^O'C^-^O ^r3:(6+0 _ .y£r2.4-^r2 ,\ 



"&4-2 6-t-2 6-1-2 6+2 £»H-2 



41. Ex ceniro Q circuliducatur QR=/7 normaliter ad lineam 



