6% DE VALORE FOKMVLAE 



§. 44. Ponamus nunc efie X— 3 et wzi ac 

 per expreflionem infinitam erit 



Cs d u\ — l z *- * ,0 '♦ l5 IO " etc 



J (J U. Ul * T . j, j. TT . T j. T ^. T g. 55 V.LV.. 



fecundo , per expreflionem finitam 



/S</u = /tang.? — /V3=i/3» 

 ita , vt futurum fit 



y 3 — !ut. !^L2. 1±-L 6 etC. 



huiusque producli valor per formulas integrales erit 

 fdy{\ -yy)~~ l 



fdy(\ -yy) 5 

 Denique formula integralis pracbebit 

 fSdu = /=5ii_~^ i- z . 



§. 45. Eodem modo etiam euoluamus alte- 

 ram formulam T cuius valor per feriem erat 



T — _i 1 v- ' — 4- ' — — 1 l-etc. 



— X — u X-t-co * sX — w jXh-co ' sX— w sM-u « 



vnde fit 



/T</u=-/(X-u)-/(X+u)-/(3X-w)-/(3X+(d)-ctc. 

 quae expreflio vt euanefcat pofito to = o, erit 

 fT</w = /c^- f£- 5*r^~ etc. 



J XX — oj w $>aX — iou 2sXa — ww 



deinde vero cum per formulam finitam fuerit 

 T = 7 \ tang. ™ erit 



/T </ w =/Vx w ran S- 7? vbi P oflto rx ^ ^ erit 

 fTdu —fd(p tang. (f> = - / cof. $ ita vt fit 

 /T tfto = -/cof. *-£; 



cuius 



