(80 == 



lin. h — fin. a — cof. ::: fin. (a — ^) z:z o . vnde fit 

 cof. z 



fin. h ■ 



Jin. [a — b] 



Corollaiiuni i. 



Cum fu fm. l^ — fin. a z=: 2 fin. ^--'' . cof. ''-± -? ct 

 fin. (« — Z') iiz — i fin. ^-^" cof. ^--^ , 



cofinus arciitJ E C zz: c; ctiara hoc modo exprimi poteft: 



cof. *^-l 



co(. x: — — . y-r— vnde fit 



cof. 'Ll- i 



cof.FC=:-cofECz=-HS^^L^); 



COl. 2 (^ — rtj 



vbi notaffe juu.ibit, ob arcus 1 (Z? -f- «) et 2 (^ — ^) qu.idrante 

 minores, fcmpcr fore coi\ l (l/ ~ a) "^ cof. i (d -h a) y vude eui- 

 dcus eft folutionem femper efle podibiJem. 



Corollarium 2. 



Cum fit col. t C ~ i , ent 



cof. l (h — ^) 



3— CofFC ,1-/-'" COf K^ — ^) — Cof ' (^-f-,7) 



1 +- cof F C coi; i{l) — a)-^ coi: i (/:• -^ r/; 



hoc cd tang. I F C' =z tr.ng. s a tang. ; Z» , fiuc ciiam 



cot. i E C" ~ tang. l E A . tang. l E B ; 

 vndc fcquitur haec egregia proprictas : quod cotangens climidii 

 arcub E C fit mcdia proportionaiis inter tangcntes dimidiorum 

 arcuum E A ct E B. 



Corollarium 5. 



Si am.bo punc'ta A et B aequidifient ab interfcctionibus 

 circulorum maximorum E et F, fibi diametraliter oppofitis, 



ob 



