MathDB
Today's calculation of Integral 866

Source: 2013 Waseda University entrance exam/Science and Technology

February 16, 2013
calculusintegrationgeometrytrigonometrycalculus computations

Problem Statement

Given a solid RR contained in a semi cylinder with the hight 11 which has a semicircle with radius 11 as the base. The cross section at the hight x (0x1)x\ (0\leq x\leq 1) is the form combined with two right-angled triangles as attached figure as below. Answer the following questions.
(1) Find the cross-sectional area S(x)S(x) at the hight xx.
(2) Find the volume of RR. If necessary, when you integrate, set x=sint.x=\sin t.