H ■ Y P E K G E O M E T R I C A, 23 



leificet ex illa aequatione differentiats colligitur \t 

 ante inclinatio tangcntis ad axem (p,. fitque 



~t— tang. <pz:q{~A-+- 7 £ rp + _^ J + _JL ? . + ctc j, 



Deinde fi pro aequatione diffcrentia'i breuitatis- gra- 

 tiai ponamus rf4/-A//w+Bu/a)4-CwVa) -f- etc. 

 crit radius curuaturae in dato* curuae puncto 



zr-^j— " "— 'b^JT^ ob A~tang.(fl Effc vero 

 B-tang.^-A + ^H- 1^,-r- feg$ -+- etc.) 



Tnde fi radius curuaturae ponatur 13 r erit 



» — 4 ^* 7 " * \(>-hpf -r- (.7+p? -t- (T^r^-r-ctc, 



20. Quo autem inireftigationera dlreclionfe et 

 ciiruaturae ad euruae pundts $ punclo principali 

 coordinatis p tt q deffnito extendere queamus r po~ 

 namus- breuitatis caufa 



- A ~*- r+p-T--^r-p) -r- ^~-f } +- t^p)-t- etc =P 



t TTfj* Hr-frqp^p -f- £~r 4. —-^ + etc# - (£ 



\ !_ __ r , ; r 



<»-+-#* ~*~ <»-+-#* ""*" r, -+-#■= -r- {—-py + etc. z R 



*-*-*>}* -4- {~7pJ+ -r- (TZpT* -h (^rpj* ~f ete.^S 

 etc 



Iami 



