(8) 



mulae r:A*, Ideoqiie ipfam formulam Fix^ In qu3 fi delnceps 

 ftatuatur x - i, obtinebitur formula F : /, quem valorem in fu- 

 perioribus potifTimum fpedauimus. Hinc igitur, comparationc 

 cum ferie generaliflima inftituta, erit X — / [a -|- (x — ^)^]» 

 atque ipfa fumma S —IT : x, fiue erit X — /(a — b -i- b x)y 

 vnde colligitur /X d x —fd x l (a — b -\- b x), 



§. lo. Cum igitur fit fd z l z zn z l z — sr, atque 



fdjl(a-hj) — (a-{-jy)l(a-]~j) — (a-hj)y ^ 

 nunc loco j fcribendo b x erit 



fbd X l (a-i- b x) — (a -i- b x) l (a -+- b x) — a — b Xy 

 ideoque 



fdxl(a-{-bx)z=: 'litlf l ^a -h b x) — ^ ^x, 



vnde colHgitur pro noftro cafu fore: 



fXdx=i (°-^+^) i^a — b-i-bx) — l--hi— x; 



•vbi in vltima parte membrum conftans y — i omittere licet, 

 quia expreffio conftantem quantitatem indefinitam per fe poftu- 

 lat, quam deinceps ex indole feriei definiri oportet. Deinde 

 vero erit i^ zrz — ^ — ;— ; tum vero porro 



i X a — b-i-bx ■* 



dx^ (a — b-i-bx)^' dx'' [a — b-i-bx)^' 



quibus valoribus in vfum vocatis erit 



IT : X =z A -i- C^-l-^ x) l (a - b -+- b x) - X -^ -J- l — ^ 



^b '^ ■^ 1.^30 — b + X 



I fci , I r 65 



• 2 • ,„ _ t. . ^ ^M ^ r—.-~, • iS 



3.4.S ' (a — 6-(-&x)5 5.6.7 " [a—b-hbx]'' 



i_ 3 ^»^ . I s &:; __pf-r 



rT?:; • ^° • [a-b-i-bx}r r^t ' ^ ' (a- b-hbx]^ ^^^* 



vbi littera A conftantem dcnotat ex indole fcrici dcfinicndam. 



§. II. Conftans autcm ifla A ex cafu quo fmnma 

 feriei cft cognita dctcrminari debct, quod ergo ficri poftct ex 



cafu 



