1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Measuring volume of spheres using triple integrals

  1. May 28, 2012 #1
    1. The problem statement, all variables and given/known data

    Screenshot2012-05-28at42630AM.png

    Screenshot2012-05-28at42645AM.png


    I'm just interested in knowing where the 4 comes from in front of the integral.
     
  2. jcsd
  3. May 28, 2012 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    hi robertjford80! :smile:

    that 4∫0π/2 is really ∫0

    i suppose the writer thought it looks confusingly like ∫00, though i see nothing wrong with it! :redface:
     
  4. May 28, 2012 #3
    Ok, pretty unexpected but I guess it makes sense.
     
  5. May 28, 2012 #4

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    In other words, they are using the circular symmetry of the figures, integrating from 0 to [itex]\pi/2[/itex], rather than from 0 to [itex]2\pi[/itex], then multiplying by 4.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook