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!

Homework Help: Integral of plane over a sine curve

  1. Feb 1, 2012 #1
    Hi, I want to verify if my answer to this problem I made up is correct?

    Suppose we have a plane z=x+y
    Lets find the magnitude of the volume of the space underneath the plane and over the REGION in the xy plane defined by y=sin(x), from 0<=x<=2pi.

    So for example, my definition of the "magnitude of the volume" is analogous to saying the magnitude of the integral of sin(x) from 0 to 2pi is 4, not 0 because we took the absolute value of the negative section from pi to 2pi.

    So first I integrate x+y dy from 0 to sin(x), then I break the integral
    over x up into 2, from 0 to pi, and pi to 2pi. Doing this, I get an answer of 4pi.

    Is my solution to what I want correct?

    Thanks so much
    Last edited: Feb 1, 2012
  2. jcsd
  3. Feb 1, 2012 #2


    User Avatar
    Science Advisor

    This makes no sense. There is no volume "over a curve".

  4. Feb 1, 2012 #3
    OK all I am saying is integrate using the domain y<=sin(x), 0<=x<=2pi, but solve for the magnitude of the volume.

    EDIT; here is the exact region I want to integate over. 0<=y<=sin x from 0<=x<=pi, and sin(x) <=y<= 0 from pi<=x<=2pi
    Last edited: Feb 1, 2012
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook