Solve Calculus 3 Question: Triple Integral over Parabolic Cylinder and Planes

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    Calculus Calculus 3
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Discussion Overview

The discussion revolves around computing a triple integral of the function z over a region defined by a parabolic cylinder and several planes. Participants are trying to determine the correct limits of integration for the given region, which includes the parabolic cylinder x = 4y², the planes z = 5x, y = x, and z = 0.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant expresses difficulty in visualizing the region defined by the boundaries and questions the completeness of the limits of integration.
  • Another participant notes that the intersection points of the parabola and line provide a bounded area in the xy-plane, suggesting that the region is indeed enclosed.
  • There is a proposal for the limits of integration: x ranges from 0 to 1/4, y ranges from y = x to y = (1/2)√x, and z ranges from 0 to x.
  • A later reply suggests that the upper limit for z should be 5x instead of x, indicating a potential disagreement on the limits of integration.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the limits of integration for the triple integral, particularly regarding the upper limit for z, which some believe should be 5x while others suggest it is x.

Contextual Notes

There are unresolved issues regarding the completeness of the boundaries and the implications of the x = y plane on the region's limits. The discussion reflects uncertainty about the correct interpretation of the geometric constraints.

marc.morcos
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Hey guys, i need some help... I am trying to compute the triple integral z dx dy dz, where R is the region bounded by the parabolic cylinder x= 4y^2 and the planes z = 5 x, y = x, z = 0 ... i can't seem to get the limits of integration... when i sketch it it doesn't quite make sense... thanks in advance...
 
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i tried again but the sketch doesn't make perfect sense, its almost like the boundaries don't limit it completely, so the volume appears to be infinitly large
i have the z=5x plane, x=y plane, z=0 plane and the parabolic cylinder x=4y^2... i don't see the use of being given the x=y plane because its just skims the parabolic cylinder, not giving it a boundary...
 
x= 4y2 is a parabola and y= x is a line in the xy-plane. They intersect at (0,0) and(1/4, 1/4) and inclose a small area between them. The region they include is the cylinder having those boundaries. z= 0 is the bottom boundary and z= x is the top. Overall, x ranges between 0 and 1/4. For each x, y ranges between y= x and [itex]y= (1/2)\sqrt{x}[/itex]. For every (x,y), z ranges between 0 and x. Your integral is
[tex]\int_{x=0}^{1/4}\int_{y= x}^{(1/2)\sqrt{x}}\int_{z= 0}^x z dzdydx[/tex]
 
thx so much... i couldn't see how the x=y would effect
 
oh and i think that z goes from 0 to 5x not 0 to x
 

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