[Aren Siekmeier]

Originally Posted by Ether

Really nice work Aren and Gus.

Here's how I did it.

Cool, I much prefer how you dropped to the double integral, I don't think about stats enough when doing these things.

Originally Posted by MechEng83

Now that this has been satisfactorily solved, I'll post a youtube video of this problem that I literally saw the week before Ether posted. I didn't feel right in just posting it, or claiming it as my own solution.

The problem gets to the 4ʃʃ(1-x)(1-y)√(x^2+y^2)dxdy GeeTwo derived, but then it does a polar coordinate substitution to make the integration "easier"
It's another approach which gives a closed form solution, demonstrating that there can be multiple ways to validly solve a problem.

While you can certainly say that there are multiple ways to solve a problem, I'll venture that the one presented in the video is considerably more elegant than mine The immediate trig sub works wonders on the rest of it.

Thanks for the link!