Calculus Volume 2 · free preview
Determining Volumes by Slicing
Solids with known cross-sectional area integrate that area along an axis to give the volume, with disks and washers handling solids of revolution as the central cases.
1. Slicing a solid into known pieces
Slicing a solid into known pieces
2. Washers and axes
Washers and axes
3. Beyond circular sections
Beyond circular sections
4. Choosing the method
Choosing the method
5. Volume integral principle
A solid lying between x = a and x = b has cross-sectional area A(x) perpendicular to the x axis. What integral gives its volume?
6. Disk method radius
The region under y = f(x) on [a, b] rotates about the x axis. What is the cross-sectional area A(x) of the resulting solid?
7. Washer area structure
A washer has outer radius R and inner radius r. What is its cross-sectional area?
8. Choosing the axis
Rotating a region about the y axis, with slices perpendicular to the y axis, what plays the role of radius?
9. Square cross sections
A solid with circular base radius r has cross sections perpendicular to a diameter that are squares. What is A(x)?
10. Sphere by disks
The semicircle y = sqrt(r^2 - x^2) rotated about the x axis gives a sphere. What volume integral computes it?
11. Cone volume fraction
Rotating the line y = (r/h) x on [0, h] gives a cone of volume pi integral of (r^2/h^2) x^2 dx. As a fraction of pi r^2 h, what is the volume? Answer like 1/3.
12. Washer outer radius
The region between y = 2 - x^2 and y = x rotated about the x axis has outer radius 2 - x^2. What is the inner radius? Answer like x.
13. Volume units
A volume integral multiplies area by thickness. If areas are in square centimeters and x in centimeters, the volume is in cubic centimeters. As a number, how many dimensions does the result measure? Answer with a number.
14. Slice thickness symbol
The thin slice thickness in volume integrals is written dx or dy. As a two-letter string, what is it when slicing perpendicular to the x axis? Answer in lowercase.
Practice this interactively
Free account · instant grading · spaced review that schedules itself.
Start this course for free