102 BrUNACOI 



F 



> (^W^')-(<>:')(^if:\ p (il) COS u ^ (If) sen u- \ 

 l^ds'^ds' ^ds'^dsni^ds' ^ ^^ds^ ' i 



ovveio 



F^tiy^cosu-^fysenu O (i/')(^\_(^')(^') ( = 

 *\^ds' *. ^ds' 'U^ds'^ds^ ^ds'^ds^^ 



F U^)^osu ^(i^yenu U(iz:)fy-(^)(i^)i 

 '+A^ds' '->-'' ^ds' '+^U^ds'^ds' ^ds'^ds'S 



Ora osserviamo die (noi scrivianio indistintaniente 



X , y , x' , y' , ec. per .r , y^ , x'^ ec) 



, ,dx, 1/ ,d^ x^ 3 



s s-H-> s ^a s' 2, d s ' 



,d X. 4 1^* /<^' ^K 3 



a: H-ao! ( )_^2_ ( )H-«^ ec. 



^ ^d s' a> ^ds ' 



j+a» 



, .a y. CD ,« Y. 3 



J •'j+u f ^d S' Q. V J '' 



^r. .^,^^. .,,. 



j+aa '' X ^d s 



II /«/v 2/" y, 



/" = y = y -H a w {-/ ) -H a 0) ( — 4^ -•- "" ec. 



,^_ ,. ,^„ „ . .dsenu. w^ xP sen ii. , 



je/i z^ =sen « -h w /^ ^ h — ( \ _f- ^^ ec. 



'+" •» ^ ds > ^^ ds^ ' 



^«.,. >.« ,. . ,d cos u. u^ .d^ cos 11^ , 



»■*■■" * ^ ds ^ 2.^ ds' -I 



F =<p[s) -^ u t 



