AD JRCrS CIRCVLARES. ^7 



vnde feqiientes exprefllones radium r continuo accuratius 

 dabunt ; 

 I. r zz^ 9-, 000000 

 II. ri^ip, 027693 



III. r:= 9, 027798 



IV. r— 9^0^1199 

 V. r— 9-,0'2.ni99 



VI. r — 9, 027799 



vnde patet formulam fextam ad multo plures adhuc figu- 

 ras valorem ipfius r cxhibituram fuifle , fi calculum vlte- 

 rius produxiflem : et quidem exprefllo fexta videtur valo- 

 rem ipfuis r ad 24 notas axadum praebitura fuifle. 



Exempl. 2^ 



47. Ellipfium non tniiltum a circulo abludentium 

 perimetros per circulum proxime exprimere. 

 Quando eJlipfis non multum a circulo differt, tum d 

 prae c erit quantitas valde parua : idcoque formulae irra- 

 tionales commode per approximationem exhiberi pote- 

 runt. Sit breuitatis gratia V {cc-\-dd)—e et angu- 



lus ~—(^ erit V{cc~\-dd ^ ^icdco^.l) —Viee-^- 

 ^cdcoC (p)-e-\-'-^ cof Cp-^:^' cof. (p'+ '-T^-coi. 



^;-Ti!f>*cof(I)*-|-etc. 



His ergo formulis loco irrationalium fubflitutis erit 



r=e--^{e-c) 



fe (cof. Cp-f-cof 2Cl)-i-cof 3(f)-f— .H-cof.(«-i )(^) 

 " (cof (p'-f-cof.2Cl)'-|-cof.3Cp'+...+cof(«-i)Cp') 



■^'i^e^ ( cof. Cl)'-|-coC 2Cl)'-f cof 3Cl)'+. . .+cof ( «-1 )(})') 



^TtSt^ (cof Cp^-i-cof 2CI) Vcof 3Cl)*4-...-l-cof («-I )0*) 



etc. 

 D a Eft 



1. 1.3 c^di , 



