I04 B U U N A C C I 



I 



ydv" fdx\ fdx'\,dy\ i.(dx.(d^y^ rdyrd^x,) 



-^'h^diir7^)-iWd'7^)} 



_j- «' ec. = .4!>> -f- fi ui' -H w' ec. 



d s ^ •«+'- Id s' ^d s ' d s^' W 



ds ' a^ ds^ ^ ) ds' 



1 I ^ r'ly ,d^cos7i ,dW. .d cos It. 



-+• a I — - jCosu > -»- w^ ec. 

 d s* ) 



,dx'\ /dx, I fdx ,,dspnii rd^Xs ) 



(— r— ) Jtf/ZM ='__ Uererz-Hw <'-— ' )-t-a — -)senu ( 



^f/j^ :»+" 'ds' \ ds' ds ^ ds'' S 



n I ,dx ,/d'senu, fd'^ Xsfdsenu, 



^\-Jd-s^^-ds^^^'^di^^^^irr^ 



ds'' S 



01 ec. 



,dy" 



—(^yx 



^ds' *+" 'ds' ■>+" ds' ^ds' 



tfdy,dcosu ,dx ,dsenu, rd^x, 



