Rotate a Circle Around the X/Y Axis - Cylindrical Shells

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SUMMARY

The discussion focuses on calculating the volume of a region defined by the equation x² + (y - 1)² = 1 when rotated around both the x and y axes using the cylindrical method. The cylindrical method formula, ∫2πxf(x)dx, is applied, but the user encounters issues with their integral simplifying to zero. Clarification is sought regarding the process of rotating around two axes simultaneously, indicating a need for a deeper understanding of the cylindrical shell method in multivariable calculus.

PREREQUISITES
  • Understanding of the cylindrical shell method for volume calculation
  • Familiarity with the equation of a circle in Cartesian coordinates
  • Knowledge of integral calculus, specifically definite integrals
  • Ability to manipulate and simplify algebraic expressions
NEXT STEPS
  • Study the application of the cylindrical shell method in multivariable calculus
  • Learn how to set up integrals for volumes of revolution around multiple axes
  • Explore the concept of cross-sectional areas and the slice method for volume calculation
  • Review examples of rotating regions defined by curves around both the x and y axes
USEFUL FOR

Students in calculus courses, particularly those studying volume calculations using the cylindrical shell method, and educators looking for examples of rotating regions around multiple axes.

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Homework Statement


Rotate the region bound by the given curve by about the x and y axis. Find the volume through the cylindrical method.
x^2 + (y-1)^2 = 1


Homework Equations


Cylindrical method: ∫2∏xf(x)dx
Slice Method: ∫A(x)dx


The Attempt at a Solution


x^2 + (y-1)^2 = 1
x = √(2y - y^2)

∫2∏x(√(1-x^2)+1)dx from -1 to 1
But this simplifies to 0... What am I doing wrong?
 
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Help, please?
 
What do you mean by rotation "about the x and y axis". I know how to rotate around a single axis but not two.
 

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