Finding the Volume of a Region

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SUMMARY

The discussion focuses on finding the volume of the region defined by the equation (x²+y²+z²)² = x. Participants explore converting this equation into spherical and cylindrical coordinates but struggle to establish proper bounds for the triple integral. A key insight is provided, suggesting that in spherical coordinates, the bounds for ρ can be defined as -1 ≤ ρ ≤ 1, while in cylindrical coordinates, a rotation of the coordinate system to align with the x-axis simplifies the problem. The recommendation is to use cylindrical coordinates for a more manageable integral.

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Homework Statement



"Find the volume of the region bounded by (x2+y2+z2)2 = x"



Homework Equations



--> Need to get proper bounds on ρ, ∅, θ and evaluate triple integral.

The Attempt at a Solution



I have tried converting this into the spherical and cylindrical co-ordinates, but have yet to get any bounds at all...

When using spherical co-ordinates, the equation turns into:

ρ3 = sin∅cosθ

which doesn't give bounds for anything..

and similarly, if I use the cylindrical coordinates:

(r2+z2)2 = rcosθ

which doesn't give me bounds either..

Am I missing something here?
 
Last edited:
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Big-oh said:

Homework Statement



"Find the volume of the region bounded by (x2+y2+z2)2 = x"



Homework Equations



--> Need to get proper bounds on ρ, ∅, θ and evaluate triple integral.

The Attempt at a Solution



I have tried converting this into the spherical and cylindrical co-ordinates, but have yet to get any bounds at all...

When using spherical co-ordinates, the equation turns into:

ρ3 = sin∅cosθ

which doesn't give bounds for anything..
Sure it does. -1 ≤ sin(##\phi##) ≤ 1, and the same for cos(θ), so -1 ≤ ρ ≤ 1, although it might be that ρ ≥ 0 by convention.


Big-oh said:
and similarly, if I use the cylindrical coordinates:

(r2+z2)2 = rcosθ

which doesn't give me bounds either..

Am I missing something here?
 
If you actually try to do it using Mark44's comment in spherical coordinates you are going to get an awfully nasty integral. Use cylindrical. And here's a hint. Rotate the cylindrical coordinate system so the axis lies along the x-axis instead of the z-axis. Or you can think of this as rotating the volume. Now you want the volume of (r^2+z^2)^2=z. Makes life much easier.
 

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