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Homework Help: Rotating about a curve

  1. Apr 30, 2008 #1
    1. The problem statement, all variables and given/known data
    Find the area of the surface obtained by rotating the curve
    y= 1+4 x^2
    from x=0 to x = 8 about the y-axis.

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. May 1, 2008 #2

    How did you try to solve it? Or don't you know how to start?
  4. May 1, 2008 #3
    Not sure how to start it.
    Any assistance would be greatly appreciated.
  5. May 1, 2008 #4


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    Is this multidimensional calculus course?

    If it is, how is surface interagrals defined?

    (post in relevant HW-section in the future, this is not introductory physics)
  6. May 1, 2008 #5


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    Hi Tranquility13! :smile:

    This is like the one about volumes.

    again, divide it into horizontal slices at distance y above the x-axis, with height dy (so the slope is dy/dx).

    what is the surface area of this slice (remember, it depends on the slope)?

    get that, and then we'll do the integral. :smile:
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