四、令D = {(x,y)| 0 ≤ 3x + 4y ≤ 2, 0 ≤ 3x − 4y ≤ 2..
四、令D = {(x,y)| 0 ≤ 3x + 4y ≤ 2, 0 ≤ 3x − 4y ≤ 2},試計算下列重積分的值: 。(25 分)