Consider the region R in the first quadrant that is bounded by the curves and
MATHEMATICS · Multi-part · AP · Calculus AB · Applications of Integration · Applications of Integration
Problem
Consider the region R in the first quadrant that is bounded by the curves y=x2 and y=2x.
The region is revolved about the y-axis to produce a solid of revolution.
Without carrying out any numerical integration, analyze how to compute the volume of the solid.
(a) Sketch or describe a sketch of region R, clearly indicating the points of intersection of the two bounding curves.
(b) Rewrite each bounding curve as x expressed in terms of y, and determine the y-interval over which the region exists.
(c) For each y in the interval found in part (b), identify which curve determines the outer radius and which determines the inner radius of the solid. Provide a brief explanation that refers to distances from the axis of revolution.
(d) Write—but do not evaluate—a definite integral expression that represents the exact volume of the solid generated by revolving R about the y-axis.