Spherical, Cyndrical or Polar Coordinates

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SUMMARY

The discussion centers on the appropriate use of spherical and cylindrical coordinates in solving integrals involving the equations z = √(1 - x² - y²) and z = √(2 - x² - y²). The participant confirms that solution one utilizes cylindrical coordinates, while they initially considered spherical coordinates. It is established that both equations represent the upper halves of spheres, making spherical coordinates suitable for the first equation. The key takeaway is that the nature of the z-bound suggests the use of spherical coordinates for integrals involving spherical shapes.

PREREQUISITES
  • Understanding of spherical coordinates and their applications
  • Familiarity with cylindrical coordinates and their use in integration
  • Knowledge of integral calculus and multivariable functions
  • Ability to interpret geometric shapes represented by equations
NEXT STEPS
  • Study the conversion techniques between spherical and cylindrical coordinates
  • Learn how to set up integrals in spherical coordinates for volume calculations
  • Explore the implications of different z-bounds in multivariable integrals
  • Practice solving integrals involving both spherical and cylindrical coordinates
USEFUL FOR

Students and educators in calculus, particularly those focusing on multivariable integration and coordinate transformations, will benefit from this discussion.

Northbysouth
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Spherical, Cylindrical or Polar Coordinates

Homework Statement


I have attached an image of the problem.

I know that the solution is number 1 but I'm having some difficulty understanding why. In solution one is it using cylindrical coordinates> My first response to this question had been to use spherical coordinates. Would it have been correct to use spherical coordinates if the [itex]\sqrt{}2-x^2-y^2[/itex] had instead been [itex]\sqrt{}1-x^2-y^2[/itex]

Any input would be greatly appreciated.

Homework Equations





The Attempt at a Solution



I know that the solution is number 1 but I'm having some difficulty understanding why. In solution one is it using cylindrical coordinates? Because my first response to this question had been to use spherical coordinates. Would it have been correct to use spherical coordinates if the [itex]\sqrt{}2-x^2-y^2[/itex] had instead been [itex]\sqrt{}1-x^2-y^2[/itex]
 

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Two forms are offered using spherical coordinates, two using cylindrical. In principle, any or none of them could have been correct reformulations of the original integral, but they have been constructed so that only one is correct. You just have to play around converting the original various ways until you can decide which one.
The nature of the z bound in the original integral does suggest spherical as the most natural, but that's not what the question is about.
 


Northbysouth said:

Homework Statement


I have attached an image of the problem.

I know that the solution is number 1 but I'm having some difficulty understanding why. In solution one is it using cylindrical coordinates> My first response to this question had been to use spherical coordinates. Would it have been correct to use spherical coordinates if the [itex]\sqrt{2-x^2-y^2}[/itex] had instead been [itex]\sqrt{}1-x^2-y^2[/itex]
It should be easy to see that [itex]z= \sqrt{1- x^2+ y^2}[/itex] is the upper half of a sphere with center at (0, 0, 0) and radius 1 while [itex]z= \sqrt{2- x^2+ y^2}[/itex] is the upper half of a sphere with center at (0, 0, 0) and radius [itex]\sqrt{2}[/itex].

Because they are both parts of spheres, yes, spherical coordinates would be appropriate.

Any input would be greatly appreciated.

Homework Equations


The Attempt at a Solution



I know that the solution is number 1 but I'm having some difficulty understanding why. In solution one is it using cylindrical coordinates? Because my first response to this question had been to use spherical coordinates. Would it have been correct to use spherical coordinates if the [itex]\sqrt{}2-x^2-y^2[/itex] had instead been [itex]\sqrt{}1-x^2-y^2[/itex]

Homework Statement


Homework Equations


The Attempt at a Solution

 

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