•^.1 ) 7« ( If^- 



§. 20. At fi fiierit Cp — ( 2 « + i )7r, ob fin. (f) — o 

 et cof. 4> =z — I , erit abfcifla 



•^ ^ — ** — (in + .)^7rir — ( «T+Tp Ct applicata 



PM~JK = 



c 



O, JU310. C 



deinde Tero prodit angulus 



A T M = po° - -■ (p =: 90° - Li«±j.l:!! , 



fiue tangens in his locis erit verticalis. Radius ofculi de- 

 jiique reperitur 



8 ^. fin. {'-^ ) TT o, 25 80 12. c. fin. (« + 5) "^ 



~" ( 2 « + 1 )^ 71 ~ ~ ( 2 ;z + ry 



Tbi fin. ( « -f- ' TT ) efl; Tel +1 vel — i, prouti numerus n 

 fuerit vel par , vel impar. 



§. 21. lam obferuauimus paulifper ante ifia loca 

 radium ofculi euanefcere ibique curuam cufpide eflfe do- 

 natam: fingulas igitur has cufpides inueftigafle operae erit 

 pretium. Ex formula autem generali hquet, radium ofculi 

 cuanefcere, quoties fuerit 



0-z tang. i (p — -'^^^ = LLLziF^ 



quae aequatio innumerabiles admittit fohitiones, vti mox 

 vidcbimus. Nunc autem pro his cafibus flatim manife- 

 llum eft fore abfciflkm x — —^f^ = ^JArh_^?£^ et ap- 

 pUcatam y ~\c. fin. (J) \ tum vero in his cufpidibus tau- 

 gens ad verticalem inchnatur angulo — 90° — ^ <$> , atque 

 adeo ad horizontalem A D augulo — { (J). 



§. 22. Quoniam iftae cufpides rcperiuntur in locis, 

 vbi angulus C|) aliquanto minor efl: quam (2« + ! )7r- ^^ 

 eas inueniendas ponamus (|)=(2 « 4-1)7: — ^w, vtfit 

 ^(P = ( « -4- 5 ) TT — 0) , qui crgo arcus aequari debet 



=r tang. ( ( « + i) tt - w ) =: — L_ — '^ 

 Jta vt habeatnr haec aequatio : (;/ ^- ^ ) tt — w = J~ , ex qua 

 quacri oportct onines valorcs anguU 00 j vbi ilatim appa- 



ret 



