交点为(0,0),(1,1)
V = ∫(0->1)∫(y²->y) siny/y dxdy
= ∫(0->1) xsiny/y |(y²->y) dy
= ∫(0->1) (y-y²)siny/y dy
= ∫(0->1) (1-y)siny dy
= ∫(0->1) (y-1) d(cosy)
= (y-1)cosy |(0->1) - ∫(0->1) cosy d(y-1)
= -[(-1)(1)] - siny |(0->1)
= 1 - (sin(1) - 0)
= 1 - sin(1)