Method2 2 大-2小={(x,y,)|√x2+y2≤z≤2,x +y2≤4} {(x,yz)x2+y2≤z≤1,x2+y2≤1} ={(r,,x)|r≤z≤2,0≤r≤2,0≤6≤2} {(r,6,x)r≤z≤1,0≤r≤1,0≤6≤2x 原式=9ror s p2 del drle dz del drIed 2re K心Method2. x y z o 1 2  = 大 − 小 {( , , ) | 2, 4} 2 2 2 2 = x y z x + y  z  x + y  {( , , ) | 1, 1} 2 2 2 2 − x y z x + y  z  x + y  = {(r, ,z) |r  z  2,0  r  2,0    2 } − {(r, ,z)| r  z  1,0  r  1,0    2 }    = rdrd dz r e z 原式  =    2 2 0 2 0 r z d dr e dz   −    1 1 0 2 0 r z d dr e dz   2 . 2 = e