例7交换下列积分顺序 1=df0,y+22aFfawy 0≤ysx2 0≤x≤2 x2+y2=8 .J0≤y≤V8-x2 D21 2 2≤x≤22 I-Jf(x.y)dxdy [V8-xi f(x,y)dx 2 2√2 例7 交换下列积分顺序     − = + 2 2 8 0 2 2 2 2 0 2 0 d ( , )d d ( , )d x x I x f x y y x f x y y 8 2 2 x + y = D2 2 2 y o x 2 D1 2 2 1 y = x 2 , 0 2 0 : 2 2 1 1        x y x D        − 2 2 2 0 8 : 2 2 x y x D  = D I f (x, y)d xd y  − 2 8 2 ( , )d y y f x y x  = 2 0 dy