--141 ) 133 ( ^fl-- 



2/ Vcof. r 2 tang. a (V cof. a -Vcof. (J)) + F : a - F : ({), 

 exiftentibus his fundionibus angulorum a et (p 



T:(p:=z2. cof Cp^' (i -+- ,f, cof. Cp' + ^-^ cof (j)* + etc.) 

 r : ct = 2 cof. a' (i -f- ,f^ cof a*4-^'- cof a* + etc). 



§. 10. Hic quidem facile patet, fi ponatur vel 

 «— o vel i$=o, fore T: 0—1,1980; nam in praece- 

 dente diflertatione inuenimus effe 



Neque etiam cafus, quo vel a vel (p angulo redo aequa- 

 lis, vlla difficuitate Idborat, quoniam manifefto fit r:^— o. 

 Verum fi ftatuatur (p == — 90% expreflio fupra data prae- 

 beret r:(— T) — o, quod autem veritati confentaneum non 

 eft. Ad lnnc difficulratem tollendam fuper axe «Z'— iso^nTr, 

 conftruatur curua aqdb ita comparata, vt eius abfciffae Tab ir, 

 f/> — (p refpondeat applicata p ^ = ycof (p, eritque area i'ig- 5« 



Cpqd—fd(^ycoi:,(^— r:(p. 



At ex priori differtatione , vbi abfciffas areasque corre- 

 fpondentes a pundo a fumfimus, conftat elTc aream 



a c d— I, 1980; 

 hinc fumto (J) zr: — 90° ~cb^ abfciffae a b manifeflo re- 

 Ipondet area a c b d a — 2, ;i^6o , ideoque habebimus: 



r:(-^)=::2,39<Jo. 



§. II. Quod fi iam breuitatis gratia ponatur 



2S ycof. (f) = 2 tang. a {Vcof.a - V cof.(p) + F ; a - T ; (p r V, 

 R 3 erit 



