20 DE LOCIS SOLWIS AD MENTEM 



fit in Z— *=^'?&±^^, et aequatio totiiis loci in 

 ^,_-(3£-tov?E^^v6T^^ qygg e(^ r^^ lineam redam, 



cujiis conftr. per §. ii. facile obtinetur. 

 Fi£. I. Nempe capiatur in PQ_ pars AC— p-, ctinL/ 



pars ABirz-j producatur CB in utramque partem, 

 etabfcindantur pra^terea inL/partesBL— B/~^^— ^— , 



in PQ_vero pars ANzi ^^ppTa^)) dudaque per N reda 

 NG, jungantur GL, et G/, partes earum LF, et 

 If funt iocus quxfitus. Nam applicatoe EF quie funt 

 in angulo LAQ_ prxbent omnes-f-J, et applicatas 

 E/", qux funt in angulo /AQ_ omnes —j. Demoii- 

 ftratio faciiis. 



Duda enim ubilibet FK/ parallela L/, fi er- 

 go AEzr.v , et K¥~j , propter parallelas FK 

 ct LB , invenientnr GB-^fc^, KEr::^^, et 

 KF—^vfcTkhV^Sz^^ adeo-que -4-J'(EF:=KF-KE) 



-3x-y-t-xV(P(3-a7)-t-V(y5'-tt$) ■ _ I £ r^ Px-H5'-xV{P|3-a7) -V: j 5_ -q..J) !I 



Qiii eft locus conftruendus. 



Si e=:-^) €t (^m^, erit etiam nunc locus qux- 

 fitus linea reda. 



V. Si in lEquatione Z-V{^^£-xx-\-"^-^x-^'-^) 



fit P(3aY— o , vel y— V' a^quatio erit ad Varabo- 



lamy cujus vertex invenietur ponendoZ— o, inde 



,enim refultat y^'^'^^^-) qu£e dat veftigium N ver- 



ticis Parabola^ G, in linea PQ. Si jam (35^- ae exi- 



ftente affirmativa ^Z-oJ^ fit negativa, fradio f^^p 



vel 2p^-;^j— AT. Ideo capienda cft in PQ^ portio 



AN 



