7a EIEMENTA 



km Urrf^dx , io qua qiiantitns ^ pr^eter litteras 

 Xi y-i P\ ^) ^" etc. infuper comple(flatur formulara in- 

 tegralem 'n—J^dx^ \bi J autcm fit funiftio folarum 

 litterarum a', j, p^ q^ r etc. inuenire variationera for- 

 inulae J7.dx~ 



Solutio. 



I Cum Z fit funcflio quantitatum A', j, />, ^ , r etc. 

 et nrrJ^fl^A.', eius diffcrentiale more confueto fumtum 

 erit huiuh formae ; 



dZ — LdTi-^-mdxi-^^dy-^-Vdp^-Qdq-^Rdr^&tc. 

 ideoqne eius variatio 



vnde variatio quaefita erit <5^/Z d x rnry ^ 7.d x ^ 



W At cum fit ^ fundio quantitatum .t, j', p, ^, r etc. 



et 'Kzz.J^dx ^ erit differentiando : 

 d'^-td'n-\-mdV'\-^^dy-\-^d.p-\-£idq+fS{dr'\-Qic. 

 hincque variatio eius 



^3=i£<^7r-f-?^<^r-+-^1^'+nxl/+S){'^'/H-etc. 

 quare cum fii n ~/3 dx^ erit ^ n — <5/3 ^a^A; ~JB 3 ^a:, 

 ac propterea : 



H-3i'4l'-+-etc.) 

 vnde rcperitur ; 



/L ^A- ^ n --JL dxjt dxSi: +-/L ^xjdxi m^ )' + ^^ 



H-aTl^-4-etc.) 

 Supereft 



