f. 35- Introdudo iterum demento dt, Tt fit 

 Jf r= yx ct ij! zr VY, 

 idcoque fumtis quadratis 



4f = X et ^ = Y, 



ftatuamus x -^y=p ^t x -y = q, ^t quia hinc prodit 

 dx* — dy^ = dpdq, erit 

 -ff.i^zr X-Y z=B(Ar-^) -h C (x* -y) 

 -+-D(jf^-y) 4-E(a--^*) 



f 3<^- Quoniam igitur eft 

 jirrr ^**'^ et y — ?n2 



* a 



his valoribus introducfli» reperietur 



X-Y:z:B^-f-G/)^4-' D f (3 pp + ^ ^) 



vnde pcr ^ diuidendo oritur 



^rSl^~^-^^p-^\^{aPp-\-qql+lEpq{pp^qq), 



f Sr- Nunc ctiam formulas quadratas primo ex- 

 liibitas differenticmus , et ftatuendo vt ante 



^XjX^^/jr et dX=zY'dy habebimus 



ai^ — X'' et —-^ -=2 Y', hincque addendo 



■^ =rX' + Y'. Cum vero iit 



X' — B 4- 2 C ^4. 3 D x^ + 4E jr' ct 



Y' — B 4- 2 C j 4- 3 Dyy 4- 4 E j'» 

 erit X''+Y'= 2B4- ^Cp+lDipp + qq)+Ep(pp+:iqq)^ 



