MathDB
Today's calculation of Integral 638

Source:

August 20, 2010
calculusintegrationfunctionrotationlogarithmscalculus computations

Problem Statement

Let (a, b)(a,\ b) be a point on the curve y=x1+x (x0).y=\frac{x}{1+x}\ (x\geq 0). Denote UU the volume of the figure enclosed by the curve , the xx axis and the line x=ax=a, revolved around the the xx axis and denote VV the volume of the figure enclosed by the curve , the yy axis and th line y=by=b, revolved around the yy axis. What's the relation of UU and V?V?
1978 Chuo university entrance exam/Science and Technology