Disk Method

Andymath.com features free videos, notes, and practice problems with answers! Printable pages make math easy. Are you ready to be a mathmagician?

Notes

Notes for Disk Method

Notes for Ring Method

Notes for Disk Method Advanced

Questions

Region bounded by:
\(f(x)=-x^2+8x-12\)
and x-axis

\(\textbf{1)}\) Revolved around x-axis




Region bounded by:
\(y=x^2\)
\(x=0\)
\(x=4\)
and x-axis

\(\textbf{2)}\) Revolved around x-axis
\(\textbf{3)}\) Revolved around y-axis




Region bounded by:
\(f(x)=x^2-2x+8\)
\(x=1\)
\(x=3\)
and x-axis

\(\textbf{4)}\) Revolved around x-axis
\(\textbf{5)}\) Revolved around \(y=3\)




Region bounded by: y=x
\(y=x^3\)
in quadrant I

\(\textbf{6)}\) Revolved around x-axis
\(\textbf{7)}\) Revolved around y-axis
\(\textbf{8)}\) Revolved around \(y=2\)



See Related Pages\(\)

\(\bullet\text{ Calculus Homepage}\)
\(\,\,\,\,\,\,\,\,\text{All the Best Topics…}\)
\(\bullet\text{ Trapezoidal Rule}\)
\(\,\,\,\,\,\,\,\,\displaystyle\frac{b-a}{2n}\left[f(a)+2f(x_1)+2f(x_2)+…+2fx_{n-1}+f(b)\right]…\)
\(\bullet\text{ Properties of Integrals}\)
\(\,\,\,\,\,\,\,\,\displaystyle \int_{a}^{b}cf(x) \, dx=c\displaystyle \int_{a}^{b}f(x) \,dx…\)
\(\bullet\text{ Indefinite Integrals- Power Rule}\)
\(\,\,\,\,\,\,\,\,\displaystyle \int x^n \, dx = \displaystyle \frac{x^{n+1}}{n+1}+C…\)
\(\bullet\text{ Indefinite Integrals- Trig Functions}\)
\(\,\,\,\,\,\,\,\,\displaystyle \int \cos{x} \, dx=\sin{x}+C…\)
\(\bullet\text{ Definite Integrals}\)
\(\,\,\,\,\,\,\,\,\displaystyle \int_{5}^{7} x^3 \, dx…\)
\(\bullet\text{ Integration by Substitution}\)
\(\,\,\,\,\,\,\,\,\displaystyle \int (x^2+3)^3(2x) \,dx…\)
\(\bullet\text{ Area of Region Between Two Curves}\)
\(\,\,\,\,\,\,\,\,A=\displaystyle \int_{a}^{b}\left[f(x)-g(x)\right]\,dx…\)
\(\bullet\text{ Arc Length}\)
\(\,\,\,\,\,\,\,\,\displaystyle \int_{a}^{b}\sqrt{1+\left[f'(x)\right]^2} \,dx…\)
\(\bullet\text{ Average Function Value}\)
\(\,\,\,\,\,\,\,\,\displaystyle\frac{1}{b-a} \int_{a}^{b}f(x) \,dx\)
\(\bullet\text{ Volume by Cross Sections}\)
\(\,\,\,\,\,\,\,\,\)
\(\bullet\text{ Disk Method}\)
\(\,\,\,\,\,\,\,\,V=\displaystyle \int_{a}^{b}\left[f(x)\right]^2\,dx…\)
\(\bullet\text{ Cylindrical Shells}\)
\(\,\,\,\,\,\,\,\,V=2 \pi \displaystyle \int_{a}^{b} y f(y) \, dy…\)


In Summary

The Disk Method (also known as the Ring Method or Washer Method) is a mathematical technique used to find the volume of a solid of revolution. This method involves rotating a two-dimensional region around a fixed axis to create a three-dimensional object. The Disk Method is often taught in advanced calculus and physics courses, as it allows students to find the volume of objects with complex shapes.

The Disk Method uses a definite integral to calculate the volume of a solid of revolution. The Disk Method slices cross sections perpendicular to the axis of rotation with thickness Δx, then sums the volumes of those infinitely many cross sections. Washer Method is the same idea, but the cross sections are shaped like washers instead of circles.

The Disk Method is closely related to the Shell Method, another technique for finding the volume of a solid of revolution. While the Disk Method involves summing the volumes of thin disks, the Shell Method involves summing the volumes of thin cylindrical shells. Sometimes Cylindrical Shells method is preferable the Disk or Washer Methods because it integrates with respect to the other variable.

About Andymath.com

Andymath.com is a free math website with the mission of helping students, teachers and tutors find helpful notes, useful sample problems with answers including step by step solutions, and other related materials to supplement classroom learning. If you have any requests for additional content, please contact Andy at tutoring@andymath.com. He will promptly add the content.

Topics cover Elementary Math, Middle School, Algebra, Geometry, Algebra 2/Pre-calculus/Trig, Calculus and Probability/Statistics. In the future, I hope to add Physics and Linear Algebra content.

Visit me on Youtube, Tiktok, Instagram and Facebook. Andymath content has a unique approach to presenting mathematics. The clear explanations, strong visuals mixed with dry humor regularly get millions of views. We are open to collaborations of all types, please contact Andy at tutoring@andymath.com for all enquiries. To offer financial support, visit my Patreon page. Let’s help students understand the math way of thinking!

Thank you for visiting. How exciting!