f2o METHOBFS CP^KVARVM. 



fundlio rijL', vti perfpicuum eft, a logarithmi?, feu redi- 

 ficatione parabolae pendet , eiitque HxzzOy fi xzizo^ 

 fui autem ponatur x~a^ tum i n.H a exliibebit fe- 

 niiffem totius fuperficiei fphaeroidis. 



92. Sit porro conoides hyperbolicum genitum 

 reuolutione hyperbolae am circa fuum axem cap^ 

 cuus centrum fit in c. Ponatur eius femiaxis transuer- 

 fus ea — c^ femiaxis autem qoniugatus ^z^Vw. Sumta 

 ergo in axe a centro c abfcifla quacunque cpz^zy, quae 

 quidem fit '^ c, erit appiicata pmzzzVn{jj--cc) , et 

 elementum hyperbolicum ^fdy V ^- ^ "^ ^^S t— . 



93. Hinc erit portio fuperficiei conoidis iftius 

 hyperbolici, ex arcu aju genita , feu abfciflae cpzny 

 refpondens zizi'nf(iyVn'[n-\-i)yy — cc). Quod inte- 

 grale cum fpcdari poflit tanquam fundio ipfius /, it^ 

 indicetur : 



JdyVn ((« H- I ) yy -cc) — By 

 fitque 0j — o, fi capiatur j zi: ^. Erit ergo fuperficies 

 conoidis hyperbolici abfciflT.e <7pirjj^ refpondens r:2 7r.0y. 



94. Comparentur hae binae formulae cum ilhs, 

 qiiac fupra §. 38. funt expofitae, et cum fit : 



■px , r dx(a a - 4- (m — i)x x)i/ m 



il.X^^J ^ (^a a -i- Qm ^,) X xf 



erit AzizaayC—m-i-^ %V[m~ i)-aaVm:, eC 



"^^'^Vim^i^zzim-i^Vm^ 

 vnde fit S(=r;,r^^ et 58 = ^, 



9S' Deinde pro hyperbola cum fit 



C) V r dy{—cc~\- [n-^^)yy)^ n 



fiat 



