=(85) = 



adiicere licct, qiio fndo crit 



.V = : » (p — : (33 fin. 2 (p -i- 21 cof. 2 (p) , 



eodcm modo 



j' =z ! 9i Cp -f- ■ ( 51 fin. 2 (P — 93 cof. 2 0) . 



Hoc igitiir c:ifu ctiam ipfc angulus in nollras formiilas in- 

 grcditur. 



§. 17. Non folum autcm cx nmplitudine (^ ambnc 

 coordinatac x ct j per formulas finitas cxprimi poflunt , (cd 

 ctiam ipfc arcus curuac s. Cum cnim fit d s zrz r d (p, ob 

 r — f^' ^ ( 51 cof -0 (p H- 5S fin. V) 0) erit 

 s — 5i/f^ ^'^ a Cp cof. >i (|) -h SS/f^ ^ a Cp fin. -vi (|), 

 vndc fumtis integralibus pcr Icmma pracmiffum crit 



J = — ^ [(2ivi-}-33<)fm.^(p-f-(51<— 23v))cof.-o(J))] 



fiuc ob 2f ^ -h >T>1 = a a crit 



s !=:'—[ (2iv}-f-330fin->l4^ + (2i<— ^vi) cof.r.Cl)) ]. 

 ax 



§. 18. Qucmadmodum iflae formuiae pro j ct j ct 

 coordinatis a" ct v inuentae ad ipfam curuam quacfitam pcrti- 

 ncnt , ita fi loco liitcrarum 2i et ^ fcribanrur 5i' et 33', illae 

 formulac naturnm cuolutac primac cxhibcbunti fimiliquc modo 

 fi loco 5i ct $5 fcribantur litterae 2i^ et 23 , eacdcm form.ulae 

 rcfcrcntur ad cuolutam fccundam , ct ita porro. Supra auicm 

 oltcndimus cHe 



2i'ra(2icofaj-t-23fin.a)); 23' = a(23con w-2ifin. w); 



2i'^= a' (21 cof 2 oj^ S fin. 2 cj) ; f&'''-a' (f& cof 2 oj- 21 fin. 2 ou) ; 

 r^^z: a' (21 cof. 3 u ^ JS fin. 3 w) ; ^'''z: a' (23 cof. 3 w - 21 fiii. 3 u) ; 

 ctc. etc. 



L 3 Tndfc 



