Multiple integration + Centroid Help.

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SUMMARY

The discussion focuses on calculating the volume bounded by the sphere defined by ρ = √6 and the paraboloid z = x² + y², as well as determining the centroid of the resulting region. The user attempted to set up the integral using cylindrical coordinates but encountered difficulties with the integration process, particularly with the variable r. The proposed integral leads to a volume calculation of -12π√6, which is incorrect. The correct approach involves proper application of Fubini's theorem and careful evaluation of the integrals.

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Homework Statement


Find the volume bounded by sphere rho = rt. 6 and the paraboloid z = x^2 + y^2
and locate the centroid of this region


The attempt at a solution

http://www.mathhelpforum.com/math-help/latex2/img/4deb41286077aabd94b30802f0e6a68a-1.gif

So Thats the integral that I made for this problem, but I'm having trouble integrating it. the rdr throws it off.

Please Help~! I am having some trouble.
 
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You first integrate with z, that gives you rz in the inside. Using Fubini you get (meaning evaluate the integral) r\sqrt{6-r^2} - r(r^2) and now continue with r and theta.
 
So when i evaluate it, I get -12pi rt6 as the answer.
Am I doing it wrong? I feel like I am not doing right. If you could, could I see how someone would do a problem like this? Evaluating integrals is a little confusing for me.

And then I need lots of help on the centroid part as well. Thanks~
 
Why don't you show us what you did and we can comment on it.
 

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