http://calc3.askbot.com/questions/Open source question and answer forum written in Python and DjangoenCopyright Askbot, 2010-2011.Fri, 25 Jul 2014 09:05:21 -0500http://calc3.askbot.com/question/179/question-2-on-quiz/I don't remember the exact wording of question #2 on the quiz but I think it asked what the area above the curve $z=-\sqrt{x^2+y^2}$ and below $z=\sqrt{x^2+y^2}$ inside the cylinder $x^2+y^2=1$; evaluate $\int\int\int (z) dV$. My answer came out to be zero but I don't think that is correct. If anybody understands this problem or has any ideas, please post them.AnonymousFri, 25 Jul 2014 09:05:21 -0500http://calc3.askbot.com/question/179/http://calc3.askbot.com/question/159/in-class-problem-5/I think that I understand how to set up the domain of this integral except for the inner integral. The question asks: "Let $D$ denote the set in $\mathbb{R^3}$ lying above the cone $z=\sqrt{x^2+y^2}$ and inside the sphere $x^2+y^2+z^2=4$. Set up the following integrals over $D$ as iterated integrals in spherical coordinates. You should think about which ones you can evaluate." would this be correct?: $$\int_0^\pi \int_0^\frac{\pi}{4} \int_0^2 (\rho^2)\rho^2\sin(\phi)d\rho d\phi d\Theta$$ comment: sorry, this is for part a.AnonymousThu, 24 Jul 2014 09:57:59 -0500http://calc3.askbot.com/question/159/http://calc3.askbot.com/question/158/in-class-problem/I am having trouble understanding #4e from todays worksheet: "Let $D$ denote the set in $\mathbb{R^3}$ lying above the cone $z=\sqrt{x^2+y^2}$ and below the plane $z=4$. Set up the following integrals over $D$ as iterated integrals in cylindrical coordinates. You should think about which ones you can evaluate. (e) An integral representing the volume of $D$." What is the significance of setting up an integral representing the volume of $D$? AnonymousThu, 24 Jul 2014 09:42:04 -0500http://calc3.askbot.com/question/158/http://calc3.askbot.com/question/152/mass-of-region-between-two-graphs/I'm having problems with #5 on the homework for Spherical and Cylindrical Problems: "Figure 1 shows a 3D domain stuck between $z=x^2+y^2$ and $z=8-(x^2+y^2)$. Find the mass of the corresponding object." so far all I have come up with is $$\int\int\int_{r^2}^{8-r^2} (r^2) dzrdrd\Theta$$ Am I on the right track at least? If so, how do I find the domain of r and $\Theta$?AnonymousWed, 23 Jul 2014 12:18:56 -0500http://calc3.askbot.com/question/152/