围成的平面图形在第一象限,二者交于O,A(1,1)
绕X轴旋转体体积 V = ∫¹₀π[(√x³)²- (x²)²]dx
= π ∫¹₀(x³- x⁴)dx
= π(x⁴/4 - x⁵/5)|¹₀
= π(1/4 - 1/5)
= π/20