... coDinh It 1.2:GiasltF.FoEe(O,a) thoallF-Foll <Ii vavo thoaHI(16) ,(17). G<;>iv, lil nghi~m da phu'dng trlnh bie'n phan (15) rl'ng vdip =£ thl ta co daub gia livE - VO~H ... khong gian trenG(x,y,z;~,17,0 = r(x,y,z;~,t'/,0-r(x,y,z;~,t'/,-0- 19 -v~i f(x,y,z;.;, 1],0 = 1 ~' 1 la nghi~m cd ban4Jr (x-,;y +(y_1])2+(z-02crlaph1.fdngtrlnhLaplacetrongkhonggianR3; ... yTaco(25),,~m)= (/- PEl v~m-l) - pA *(A 'J~m-I)- F)v8i fJ nhu'trong Djnh Iy 1.3(26)Mellh d~ 1.2: Gia sarv~ thoa (16), (17). Khi do sai s6 giii'a v~m) va vo 13Ilvlllll - vII< ('...