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u=x-1
v=y
D->u^2+v^2=1
x²+y²-3 = (u+1)^2+v^2+3=u^2+2u+v^2-2
â«â«ï¼x²+y²-3ï¼dxdy=â«â«u^2+2u+v^2-2dudv
å
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â«â«-2dudv=-2*é¢ç§¯=-2Ï
â«â«2ududv=0 ç±å¥å¶æ§å¯å¾
â«â«u^2+v^2dudv=2â«â«u^2dudv ç±åæ¯ç伦çæ§å¯å¾
令u=rcosQ
v=rsinQ
2â«â«u^2dudv=2â«â«u^2dudv
=2 积å[0,2Ï]dQ 积å[0,1] r^3cos^2(Q)dr=Ï/2
äºæ¯é¢å£«=Ï/2-2Ï=3Ï/2
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