De REVOLUT. DUOnUM CORPORUM, ETC. 431 



(It ' dt ' 'lit ■ (k ' ' dt '~ ' dt 



Temporis aulein priocipio , ia quo est 



habebimus 



dx df dz 



lh='' Ih—^' Tt—^' 



^^AJm-wO-D y^ D- z__^" 



m-\-n iii-\~n m-^n 



d\ C dY C dZ C" 



dt m-i-n dt m-f>n dt m-t-ri 



et consianlium valoribus substuiuis (num. 2. 3.) 



X= ; Y=Oy Z=0 



m-^-n 



dH ^ Ti{e—e') _ dY _ n(f—f') _ dZ _ n(g—g') 

 dt m-{-n dt in-\-n dt ~~ in-\-n 



Posiio demum 



hz=i/\X'-i~Y'-^Z'\ , 

 erit 



r=/K^-^')*-*-(7-j')'-4-(=-z')'i= 



n 



= — ^ .R. 



II 



21. Ope aequationum (F') ex aequationibus motus puncii 

 M (num. 7) elimlnenlur variabiles (x — x), (y — y), (z — z), 



, dx , df dz 



d . — J d . _, d . — -— , alque r ; hae tres orientur 



dt dt dt ^ ^ ' 



tfX. 7iJrXdt 



'■■dr-^-R-=''- 



. dV n%Ydt 



d . 1 =0 ; 



dt Yk 



, dZ nrrZdt 



</.-7-H =0: 



dt U 



T. VII. 56. 



