Practice Volumes of Revolution in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Finding the volume of a three-dimensional solid formed by rotating a two-dimensional region around an axis. The disc/washer method uses circular cross-sections perpendicular to the axis; the shell method uses cylindrical shells parallel to the axis.

Spin a flat region around a line, like spinning a pottery wheel. The flat shape sweeps out a 3D solid. To find its volume, slice the solid into thin pieces (discs, washers, or shells), find the volume of each slice, and add them upβ€”which means integrate.

Showing a random 20 of 50 problems.

Example 1

easy
In the shell method about the yy-axis, what is one shell's volume for height f(x)f(x) at radius xx?

Example 2

medium
Region under y=x2y=x^2 from 0 to 2, revolved about the yy-axis using shells.

Example 3

easy
Find the volume when y=xy=\sqrt{x}, 0≀x≀90\le x\le 9, is revolved about the xx-axis.

Example 4

challenge
Region bounded by y=x2y=x^2, y=0y=0, x=2x=2 revolved about the line x=2x=2 using shells.

Example 5

medium
The region under y=1/xy=1/x, 1≀x≀31\le x\le 3, is revolved about the xx-axis. Find the volume.

Example 6

easy
What goes wrong with V=Ο€βˆ«01f(x) dxV=\pi\int_0^1 f(x)\,dx for a solid of revolution?

Example 7

easy
Region under y=xy=x from 0 to 1 is revolved about the xx-axis. Set up the disc-method integral.

Example 8

easy
Find the volume of the solid formed by rotating f(x)=xf(x) = \sqrt{x} around the xx-axis from x=0x=0 to x=4x=4.

Example 9

easy
Find the volume of the solid formed by rotating y=2xy = 2x from x=0x=0 to x=3x=3 around the xx-axis.

Example 10

medium
Region under y=xy=\sqrt{x} from 0 to 1 revolved about the yy-axis (disc in yy).

Example 11

medium
Find the volume when y=x3y=x^3, 0≀x≀10\le x\le 1, is revolved about the xx-axis.

Example 12

medium
Region under y=xy=x from 0 to 2 revolved about the yy-axis using shells.

Example 13

hard
The region between y=x2y=x^2 and y=xy=x, 0≀x≀10\le x\le 1, is revolved about y=1y=1. Find the volume.

Example 14

medium
Use the washer method to find the volume when the region between y=xy=\sqrt{x} (outer) and y=xy=x (inner), 0≀x≀10\le x\le 1, is revolved about the xx-axis.

Example 15

easy
Find the volume when y=xy=x, 0≀x≀20\le x\le 2, is revolved about the xx-axis.

Example 16

easy
Which method (disc/washer or shell) is natural when rotating about the yy-axis but integrating in xx?

Example 17

medium
Region under y=x+1y=x+1 from 0 to 2 revolved about the xx-axis. Find the volume.

Example 18

medium
Region under y=x2y=x^2 from 0 to 1 revolved about the xx-axis. Find the volume.

Example 19

medium
The region bounded by y=xy=x, y=0y=0, and x=1x=1 is revolved about the line y=βˆ’1y=-1. Find the volume.

Example 20

medium
The region under y=x3y=x^3, 0≀x≀10\le x\le 1, revolved about the yy-axis using shells. Find the volume.