■ ■ ■ ■ ■ ■ ■ ■ ■
7 Applications of Integration to
Geometry
CONCEPTS AND SKILLS
In this chapter, we will review using definite integrals to find areas and
volumes; specifically area under a curve,
area between two curves,
volumes of solids with known cross sections,
and volumes of solids of revolution (using disks and washers).
We’ll also review related BC topics, including
arc length;
arc lengths, areas, and volumes involving parametrically defined
functions; and area and arc length for polar curves.
Also for BC Calculus students, we’ll review the topic of improper integrals,
including
recognizing when an integral is improper
and techniques for determining whether an improper integral
converges or diverges.
A. AREA
To find an area, we
(1) draw a sketch of the given region and of a typical element;
(2) write the expression for the area of a typical rectangle; and (3) set up the
definite integral that is the limit of the Riemann Sum of n areas as n → ∞.