Disk Method

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.

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