== (13-) 



Hic iternm pnrtes primn et tcr:i;i contnihi pofTcnt, fed prnefta- 

 bit foririulis primo inuentis vti. Hinc iam iftam tradationem 

 fcquenti Theorematc concludemus. 



Theorema. 



§. 59. Pofito z — V ( cof. Cj) -h )/ — I fin. Cj)) , fi fta- 

 tuatur f -~^ — P -i- Q |/ — i , hae quantitates P et Q ita 

 exprimentur : 



r- ,V |/ [ I -2 r cof. (6c°-4))h- c ^^'] -4- J- A tang. " ^'" ';°° ^, 



P =/-f-3/j/[l-f-2C-COf (|)-+-Z't'J 



^_^ / / [ X _ 2 c cof ((5o°^(P >-^.r.r] + ^ A tang. ^-^^^^^) 



;--±-//[i-.^cof(6o--cp)^c^c]-iAtang. ,:f-;;;-j;^, 



_H'Atang " ''^ ■ ^ , 



-L_/ /[1-2 c' cof.(6o°-^(p)-4- 1? c']+^ A tang. -:ii^°-±^ . 



Corollarium. 



§. 60. Si ergo fumamus anguhim CP r o, vt fiata;— i;, 

 pro formuhi integrah /j-^;^ — P -f- Q / — i erit: 



- W / ( I - ^^ ^ •I' --^ ) -+- -f 3 A t a n g. ;i^ ; 

 Pz=<;-+-^//(i-+-c) 



- ^ / / ( I - ^, + r c) -^ ^ A tang. ^^ 



— _V / / ( I — 1; -+- "-'i') — •« A tang. 



2 V 3 



2 01 



j_ / / ( I _ -u -4- 1":') -+- 6 A t.ing. :j;^ 



Sicque erit (^-O^ vti natura rei poftuhit. Nam quia ipfi for- 

 mula integranda eft realis, etiam integrale parteni imaginariam 



con- 



