Opuscula ,* / 1 29 
que s.i — pp^^y effet ordinaf:a Imaglnarla; reciirfus igitur 
habendus erit ad noflrum Theorema , in quo habetur p p — i 
— quantitas pofitiva , &, dp ~ , s = ~ 
^^^ , j & s . p p — i ^^^'^"^ j coordinat^ vero noilr^ cur» 
a a — XX 
YX erunt ^,;;;?— =: — 7, 
= z<!; & s . p p — i-f- y = V' '^i'* erit 
xx^aa^j.nd^^ Quantitati radicali fignum affirraativum 
X ' X 
prseponere debes , quippe quia fum^tis coordinatarum y , u 
differentiis , invenies dv ^ dx » ^^^"^ — . aa ~ i & du-:=:z, 
axx 
xx-\ aa. atque exiftente q ^ ~ ^ facla fubftitutione ha- 
- ,. aa — XX" - XX I X 
bebis ^= ~ , & i'-qq-~~,s/i-—qq — ~, atqlie 
du s/i—qq — yj du^ — d'/ == "^'^J ^^o^ ^ft dif- 
jerentiale quantitatis — • -h j . 
§. 19. Ut pervenias ad optatam conflrudionem calculum 
ulterius promoveas oportet , inveniendo nempe D \J i — q q 
dx ^ d II %ax^ ~\- a ^ . . ^ 
= ^ ^ = ^ / ^ . » ^^'^ = 
2 ar 
— ' quantitatem algebraicam arcui curv^s quasfit^ conjun- 
gendam ; ex quo flt f —J-- 2: q q -~ s . p p — i+L™ 
3s:.r-r-«« coordinatae vero curvse adhibendx 
ax X 
lunt Sq^ ■ . , fraq Ji-^ 
Qiiantitati L fignuni afnximus; nam 
» X 
fumpt is coor dinatarum diiferentiis la'^ -h aa x x 6 x"^ . 
dxa^/aa — xx ^ ■ axdx . , 
T.KP.II. E. dra- 
