fin, fin. r zz r =: cof. « ^ ^ , 



hoc efl: cofHUis anguli, fub quo tangens furfum duda ad 

 axem OC inclinatur —r, (Cf. §. 19.); reda autem ue 

 iinum eiusdem anguli exhib.bit , ita vt fit 



u e — y{i — rr) — y{p p -\- q q) ^ 

 quae etiam definiri poteft ex trianguio edu^ in quo cfi: 



u d — cof. r et ^ ^ — fin. r cof, , 

 Ynde fit 



u e~y{i -fin. O^fin. r'). 

 Hinc autcm deducitur tangens anguii due, fcil. 



tang. due — ^y^ — cof. tang. r , 

 ad quam cuoluendam ponamus breuitatis graria : 



y [u u V V -^ u u IV 'iv -\- V V IV w)—(d , eritque 



cof. = "^ et tang. r - ®" , , 



" iu [qv — ■£ u)' 



vnde fit 



tang. duezz — -i^^L^— . 



3 IM [q V — p u) 



Quare cum anguli O ?/ w tangens fit -^ , hinc rcperiemus 

 tangentem anguli 0«^, fcil. 



tane. O u e — ''L^^^Ii y - p u) - r u jjv 



ij u iu {.^ V — p u} — f- r u "v v' 



cuius fradionis numerator ob --1-— — —^, fiue 



reducitur ad hanc formam; q vj {u u -\- v v), denomina- 

 tor vero, ob 



g IV -i- r V z:z~ ^^-^ , 

 reducitur ad : — p -iv {u u ^ v <v)f ex quo colligitur 

 tang. 0«^ — — -1. 



G a §. 20. 



