I=「Px+Q+R ∫U-b6-)+(1-)-x +(x-y)d[b(1-- I(1+)y-b+[b-(1+-)xdy 2(1+) dxdy Green公式 =-2m(+b = + +  I Pdx Qdy Rdz  = − − + − − C x dy a x dx b a x [ y b(1 )] [ (1 ) ] ( ) [ (1 )] a x + x − y d b −  = + − + − + C x dy a b y b dx b a b [(1 ) ] [ (1 ) ]  = − + D dxdy a b 2(1 ) Green公式 = −2a(a + b)