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Homework Help: Proving a volume of a cylinder

  1. May 22, 2006 #1
    1. Show that a volume of a clyinder equals to v= A^2 \ (4πh)
    where h= height of the cylinder
    A = area of a original paper

    how would i prove this question?
    could any one please help
    thank you

    v= πr^2 h -------1
    v=A^2 \ (4πh)-----2

    i tried to make h da subject but i got 4v^2 = Ar^2 which it does work out
  2. jcsd
  3. May 22, 2006 #2
    What is the curved surface area of a cylinder ?
    Is it the area of paper used ?
  4. May 22, 2006 #3
    yes the area of the paper is used
  5. May 22, 2006 #4
    Since this is in the precalculus forum, i won't refer to integrals. The regular expression for the volume of a cylinder is nr^2h. The area of the paper is A. Find an expression for A in terms of n, r and h, and simply square that and divide by 4nh to show that this equals the volume of the sylinder.
  6. May 22, 2006 #5


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    Just for the record, I prefer the integral form, much nicer and easier to understant I find.

  7. May 23, 2006 #6
    thank you for your help though
  8. May 23, 2006 #7
    what is the meaning of "putting the 2 functions in the parathesis seperated by the colon" ?? :bugeye: :bugeye:
  9. May 23, 2006 #8
    what's the meaning of
    "A = area of a original paper"

    yOU skipped the most important part !?
    by folding a paper to form a cylinder !? I assume..
    V=πrrh = 2πrh2πrh\4πh = AA\4πh

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