TERRESTRIBVS. 475 



rcpcrlemns 



S5 — M ( —^ — — j; — — mr, _ ,^ 





(l=:-M(_{i-k)m-^ri)-^'— 



■ ^ TO(i — ? &)— _ 



m — X 



m (t — 3 ft) — 5 



* m{5- zk:-j~ . 



§. 5. NuiiC igitiir ad interualla lentiui-n re- 

 fpiciamiis, ac prijmim quidem erit — « ( i — ,— -v-,] 

 qiiod femper eft pofitiuum ob k <^ i , fecundum au- 

 tem crit — — ^(i-f-t)) quod pofitiuum efTe ne- 

 quit nifi B fit numerus negatiuus. Cum* igitur nu- 

 merator ipfius B fit pofitiuns , denomiiiator nega- 

 tiuus effe opportet, "vnde fequitur 4. jk <^ 3 et a:. <^ *, 

 tertium autem interuallum eft r-,— ^f— (2— ^) vn- 

 de patet BC efle debere ncgatiuum j quia igitur B 

 iam eft negatiuum , opportet eife C pofitiuuin; cb 

 numeratorem vero ipfius G negatiuum, videarnus an 

 denominator etiam negatiuus reddi poiTit : qaod cum 

 lieri nequeat , patet liunc cafum locum habere non 

 polfe , quo erat P ^ o. 



§. 6. Tribuamus igitur litterae P valorem ne- Csfus quo 

 gatiuum , et nunc vel (^ vel R debet efle ncgati- ^*^° *' 

 vum. Sit primo Q negatiuum et ponamus Q^ — — k ^ 

 crit I — I — j— =: o , vnde fit R — ^£j-^ ficquc R 

 debet effe pofitiuum ,' crit igiiur 



^ k — 1 



ideoque 



p __ _ mjk_-^ gj P Q ■- + ?« (/: - 1) 



O 2 vndc 



