x²-x+1/2²+(2y)² -y+1/4²　≤1/4+1/16=5/16
(x-1/2)²+(2y-1/4)²≤5/16,　(x-1)²+ 4 (y-1/8 ) ² ≤5/16
向左向上平移x,y,得：x²+4y ²≤ 5/16,化为椭圆的标准方程：
x²/ (5/16 )+　y²/ (5/64 )　≤1,
化为参数方程:x=5/16 cost,y= 5/64 sint

代入 ∫ ²π← ₀　(5/16　cost -1/2)+( 5/64 sint -1/8 )
d (5/16cost ) (d5/64sin t)

化简- 125/8192 ∫... (1/2 cost +1/8sint -1 ) sin t cost dt
...∫1/2 sint cos ² t+1/8 sin ² t cost -sint cost dt
在4倍第一象限积
-125/2048 [ π/²←₀ ] [ -1/6 (cost)³+1/24 (sint)³ +1/2(cost)² ]
... [ 1/6 +1/24 - 1/2 ]=
125 * 7
--------------
24* 2048

逆用形心公式会方便些