Volumes by disks
Grade 12 Math Worksheet

Circle the best answer, or write your answer on the line.
The region between y = x² (x ≥ 0), the y-axis and y = 4 spins about the y-axis. Ari uses horizontal disks. Write the volume as V = kπ. What is k?
The region between y = x² (x ≥ 0), the y-axis and y = 9 spins about the y-axis. Bo uses horizontal disks. Write the volume as V = kπ. What is k?
The region between y = x² (x ≥ 0), the y-axis and y = 1 spins about the y-axis. Esme uses horizontal disks. Write the volume as V = kπ. What is k?
The region between y = x² and y = 4 spins about the line y = 4. Kira uses disks. Write the volume as V = kπ. What is k?
The region between y = x² and y = 1 spins about the line y = 1. Luz uses disks. Write the volume as V = kπ. What is k?
The region between y = x² and y = 9 spins about the line y = 9. Milo uses disks. Write the volume as V = kπ. What is k?
Pia spins the region under y = √x, 0 ≤ x ≤ 25 about the x-axis. Which integral gives the volume?
- π ∫ from 0 to 5 of x dx
- π ∫ from 0 to 25 of x dx
- π ∫ from 0 to 25 of √x dx
- π ∫ from 0 to 25 of 2√x dx
Ren spins the region under y = 2x, 0 ≤ x ≤ 5 about the x-axis. Which integral gives the volume?
- π ∫ from 0 to 5 of 4x dx
- π ∫ from 0 to 5 of 4x² dx
- π ∫ from 0 to 10 of 4x² dx
- π ∫ from 0 to 5 of 2x dx
Tala spins the region under y = eˣ, 0 ≤ x ≤ 1/2 about the x-axis. Which integral gives the volume?
- π ∫ from 0 to 1/2 of 2eˣ dx
- π ∫ from 0 to 1/2 of e^(2x) dx
- π ∫ from 1 to √e of e^(2x) dx
- π ∫ from 0 to 1/2 of eˣ dx
Zee spins the region under y = 1/x, 1 ≤ x ≤ 4 about the x-axis. Which integral gives the volume?
- π ∫ from 1 to 4 of 1/x² dx
- π ∫ from 1/4 to 1 of 1/x² dx
- π ∫ from 1 to 4 of 2/x dx
- π ∫ from 1 to 4 of 1/x dx

