•*g ) 323 ( §» 



que habeatur ^__*-§. c -|, vbi J | = cof. C E B — cof. i 



et c — = tang. <$) , fiet tang. _ — tang. <$>. cof. / , hincque 



cot. _ = ____^ls- , £__. 4- cot. v) , quae formula caeteroquin 



hunc in modum elici poteft. Pcrinde ac fupra (5) de- 



monftrabitur, effe J{=_^B' hinc fiet tfr__ = fvS 

 eft vero ob BF.EF-EB, |f-|f = §-j - |? , hincque 



|! = cot. «,;;■= cot. * !JJ =_£-i, H = cot. X, J-| __ tang. * 



prodit cnt. _ = cot. n-T- J * t - < -%. 3 V* t * < - Pf ° faciliori com " 

 puto huius formulae, poni quidem pofiet cot y = __i£^i2-_?, 

 vnde fieret cot. _ __ cot. vj -+- cot. y = ^y^V 1 verum 

 mox aliam formulam pro _ computando , mclto concin- 

 niorem fuppcditabimus. 



§. 11. Scilicet in formula cot. _ _cot.\i+ /7 "- ,3 ^y g - < , 

 ponatur cot. t — cot. Afin.t., eritque cot. _ _: cot. ■>] + — • J t a g, - x , 

 hinc cot. _ - cot. v) — ________ , vnde fahiSzSl = SSfci et 



j' • jJi.tD toag. * 



proinde /"»-**•[»;-"> = __*____'___; , fi ue 

 tang. ( _ - * 7,) = tang. J v, £££$ , 



quae formula ob datos angulos tj, tt et /, dabit Valorem 



ipfius w. Cacterum hac quoque ratione ad formulam iftam 



j i..M--« uj— rjmg.j peruenire licet e x pundo D (Fig. 6.) 



in bafin trianguli Sphaerici G H demittatur arcus norma- 

 lis D K, tumque facili attentione adhibita patebit, efie ar- 

 cum GK menfuram anguli E S B _r co, arcum HK men- 

 furam anguli B S T = -yj — _, nec non D K menfuram an- 

 guli C S B __r. lam vero eft in triangulo Sphaerico DGH: 



tang. H : tang. G __ fin. G K : fin. H K , ideoque 



tang. 7r: tang. ; = fin. _: fin. (y\— _). 



SSZ §. 12- 



