求由曲线x2=ay与y2=ax(a>0)所围平面图形的质心(形心)

2025-12-17 22:40:40
推荐回答(2个)
回答1:

曲线x^2=ay与y^2=ax(a>0)交于点(0,0),(a,a).
由曲线x^2=ay与y^2=ax(a>0)所围平面图形的面积
S=∫<0,a>dx∫dy
=∫<0,a>[√(ax)-x^2/a]dx
=[(2/3)x√(ax)-x^3/(3a)}<0,a>
=a^2/3.
由曲线x^2=ay与y^2=ax(a>0)所围平面图形的质心坐标:
x'=∫<0,a>xdx∫dy/S
=∫<0,a>[x√(ax)-x^3/a)dx/S
=(3a^3/20)/(a^2/3)
=9a/20.
y'=∫<0,a>ydy∫dx/S
=9a/20.

回答2: