TROBLEMATIS GEOMETRICL aa^ 



fiii. ( ^-2(|)/ — fm J'cor.2(p'-2 fini cofJfin. 2(f>cor2(I)-|-cor.0Tin.2(J)* 

 Vnde ciim fit ee fin. z(p'—ff{Cm. ^- fin. ( 0-2(P)*) erit 

 ob I - cof 2<P'=: fm. 2 (p' : 



finr-fin.(e-2(p)'3fin.rfin.2(I)^-f2fin.0cofefin.2(pcof.2(p-corffm.2((i* 

 Ateft 2fin.0cof ^=:fin.2^ et cof ^— rm.O'— cof.2 , ergo 

 fm.T-fin.(d-2CP/zz;fm. 20fm. 2(pcof.2(J)-cof. aOfm. 2(p' 

 ficque erit , 



f ^fm. 2(()"-njf fin. aOfin. 2(1) cof. 2(I)-/cof.-20fm. 2<p^ 

 quae diuiCi per fin. 2(J) dabit 



^^fin. 2(1)— /fm. ^Ocof. 2(p-ffcor. zHin. 2 (|) 

 cx qua tandem elicitur : 



coj. 2 $ '^'"'5- 2. 4-» ee^J-Jcoj.29 



Inuento ergo angulo ECM~2(J) cuius tangens cft rr 

 ?7^^3^ i fi 'li'^ '^"§"l"s bifecerur reda CA , haec iam 

 erit poiicio alterius axis principalis , cuius quantitas ita 

 definitur. ^ 



Dcmiflb ex E in CA perpendiculo ER, dudaque ad 

 E tangonte ET, quae ipfi CF erit paralleia , donec ipfi 

 CA produdae occurrat in T , ex natura tangentis con- 

 fiat fore CA mediam proportionalem inter CR et CT. 

 lam obi CE = ^ et ECA— (|) erit ER— ^ fin. (J) et 

 CR— ^ cof. (J^. Tum ob ang : CTE=:^-(|) erit 

 ^ *■ — /M. [o-cp; et V- 1 — j,^, ^g_^y 

 Hinc itaque erit : 

 femidxis C A =r f V yT^^T^jjH^. 



Alter femiaxis ad CA erit normalis , qui fi intelligatur 

 linea C B repraefentari , cum fit 



F f z KE'~ 



