DE CONSTRrCTIONE AEQFJTIONFM. 69 



§. 7. Ad h;inc aequarionem vlterius reducendam, 

 pono du — -^- , entque ibqdr-\-^brdq—r dt—r qqdt\ 

 in qua / et r a fe mutuo pendent , qui t t^di ■— k Q^, 

 et bIr=:QN. Porro fiat qr—s feu q—~ erit zbds 

 — rdt — '-^'. Sit nunc ^ — zbdz et rdt— zbZdz,. 

 erit rrrrZ et /' — VZ. Praeterea eft dt-zz: ^b-Zdz' 

 et t—2bJdzVZ. Per xs igitur curua BN ita deter- 

 minatur, vt fit A(^z^2bJdzVZ et Q^N — f/Z. Qiiia 

 ergo curua BN datur, dabitur fimul Z per s. Fa- 

 dis autem his fubftitutionibus habebitur ds-i-ssdzziz 

 Zdz. 



§. 8. Propofita ergo aequatione ds-\-ssdz—Zdz 

 valor ipfius j per z lequenti modo poterit definiri. Con- 

 ftruatur curua BN huiusmodi vt fumta abfciflli AQ^— 

 zbJdzVZ, fit applicata Q^N — ^/2. Tum filo lon- 

 gitudinis b fecundum curuam BN protrado defcribatur 

 tra<floria AM. Deinde ducatur tangens MN, quae 

 etiam ipfo filo exhibebitur, innotefcctque angulus MNQj 

 cuiui dimidii tangens fit —q. Hoc fiido erit s—qr 

 — qVZ. 



§. 9. Coordinatae autera AP et PM curuae tra- 

 Aoriae ita fe habebunt: erit AT — x — t - :^jj~_:p-^ — t 



eft t—zbJdzVZ et U — \1Z.^ atque ^— ^ — /^; erit 



x^ibJdz-VZ—'^ et.r = 1/2-4-^^^. Ex 

 his iam aliae nafcuntur conftru^flioncs aequationis ds-\- 

 ^sdzzizZdz. Per motum cnim tracftorium innotefcunt 



I 3 coor- 



