i4<J DE CALCVLO xM O T V S 



XVL 



Ciiin trcs acquatioiies ex principiis mcchani- 

 cls dcdiiclac totidcm dctcrminntioncs fiippeditent , 

 totiim artificiiim in hoc conftiu , qucmadniodum cas 

 indc commodilTime dcriucmns. Ac primo quidcm 

 ftatim fe offert haec ratio , qua prima pcr ^r/X 

 fccunda pcr idY ct tertia pcr sr/Z multiplicatae 

 in vnam fmmam colliguntur ^ quia enim \t fupra 

 vidimus e(l 



r/X* ^dY^-^-dZ'- d-v* H- 1- v d(^' 



et XX-i-YY-j-22 — .-."y 



crit ^dXddX+zd Ydd Y-\-zdZ ddZ-d. {d-v ^r^cvd^^) 



ct Xr/X-t-Yfl^Y-l-Zr/Z^T^-j. 



Qiiarc merrtorata ratione pcrucnietur ad hanc ac^ 

 qnationem : 



d. {dv"+ v vd(p')--2adfC-^dv-^ p ^^dv - Bii {dXcoC.I> 



^dYfxiuy~-i^):) 



vbi formulam ^xcof O-f-rt^Yfin. euoiui conuenit. 

 Verum ex formuHs fupra §. lo. erutis colligimus: 



ob Z:zit'fin. o-fin.u vndc fit 



«/Xcofa+^^Yfm.O^^fXcofO + Yfin.O)-^^-^ 



modo autcm vidimus eflc 



Xcof O-i-Yfin.O^i^^coCo-cof (0-v^)+ fio.o-cofw fin (^0j) 



— .vcof (X 



tum 



