Definite Triple Integral to Series

Elysian
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Homework Statement



Does the triple integral
\int^{1}_{0}\int^{1}_{0}\int^{1}_{0}\frac{1}{1+x^2 y^2 z^2} = \sum^{∞}_{n=0}\frac{1}{(2n+1)^3}

Homework Equations





The Attempt at a Solution


I've not a single clue on what to do with this problem. I figured maybe I could find a decent conversion of variables and find the Jacobian and switch variables to make this easier but tht didn't seem to work.

I don't know why but I think the series expansion of arcsin or arctan is needed here, but I'm not exactly sure how to incorporate it in. I don't even know how to evaluate this triple integral..
 
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Elysian said:

Homework Statement



Does the triple integral
\int^{1}_{0}\int^{1}_{0}\int^{1}_{0}\frac{1}{1+x^2 y^2 z^2} = \sum^{∞}_{n=0}\frac{1}{(2n+1)^3}


Hint: the integrand is ##\leq 1##, so does that give you an upper bound for the left hand side? Notice also that the first term of the series on the right hand side is ##1##, so that gives you a lower bound for the right hand side.
 
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jbunniii said:
Hint: the integrand is ##\leq 1##, so does that give you an upper bound for the left hand side? Notice also that the first term of the series on the right hand side is ##1##, so that gives you a lower bound for the right hand side.

Ohh I think I get what you mean

The upper bound for the LHS is 1, and the first term of the right hand side is 1 and then adding constants, so they can't be equal?

There's only one intersection of their ranges so it doesn't work out then I guess?
 
Elysian said:
The upper bound for the LHS is 1, and the first term of the right hand side is 1 and then adding constants, so they can't be equal?
That's right, the LHS is ##\leq 1##, and the RHS is ##> 1##, so they can't be equal.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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