... cae gii thi~t (3 7), (3 8) ta e6 FE L2(I), (Jdily F xac dinh theo (3 6) .Mellh di 1.4:VvEL2(J) ; p(x) =(1 +lxI)2B~t (Av)(x) = Jv(C ;)1 n!x-c;ldC; (4 0) JKhi d6 :A: L~ (J) ~ L2(I) 13. loan t:U'tuy~n ... vdi :in ham v(x.y)nhu'san:IIv(~,17)d~d17J. Z Z F(x,y) . (x,y) E 0 (5 3) Q (x- ~) +(Y 1 7) IIUI(~ ,17)d~d17F(x,y)=-21fUo(x,y)- Ja (X-~)Z+(y-17)Z-HI f(~,17,t;)d~d1]dt; (5 4) R?J(x-l;)z+(y-17)z+t;Zvdi 3. ... co,O:<:;z:<:;;(x,y)}vdi 4>thuQc ldp C1(R 2) T1m ham UE C2(D)rC 1( D) thoa .61 -1=0 trong Dux(x,y,9'{x,y )) = f(x,y) ,uA x,y,qj(x,y )) = g(x,y)uA x,y,qS(x,y )) = h(x,y)u (x,y,qj(x,y )) = u1(x,y)vdiJ....