Let region in the –plane be bounded above by and below by the –axis on the interval
MATHEMATICS · Multi-part · AP · Calculus AB · Applications of Integration · Applications of Integration
Problem
Let region S in the xy–plane be bounded above by y=x and below by the x–axis on the interval 0≤x≤4. Two solids share S as a common base.
• Solid C has cross sections taken perpendicular to the x–axis that are squares.
• Solid D has cross sections taken perpendicular to the x–axis that are rectangles whose height at each x equals one–half the side length of the corresponding square cross section of Solid C.
Respond to each part. All work must be shown.
(a) Express the side length s(x) of the square cross section of Solid C as a function of x. Hence write an algebraic expression for the cross–sectional area AC(x).
(b) Express the cross–sectional area AD(x) of Solid D in terms of x.
(c) Write, but do not yet evaluate, a definite integral representing the volume VC of Solid C, and a separate definite integral representing the volume VD of Solid D.
(d) Evaluate both integrals to obtain VC and VD, then compute the ratio VCVD. Simplify your answer.