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Homework Help: Show that its volume is a maximum

  1. Apr 28, 2010 #1
    1. The problem statement, all variables and given/known data

    A right circular cone has base radius , r and height h . As r and h vary its curved surface area is kept constant . Show that its volume is a maximum when [tex]r=r\sqrt{2}h[/tex]

    2. Relevant equations



    3. The attempt at a solution

    A= pi r^2 + pi r root(r^2+h^2)

    V=1/3 pi r^2 h
     
    Last edited: Apr 28, 2010
  2. jcsd
  3. Apr 28, 2010 #2
    Re: differentiation

    what is m?
    [tex]
    r=r\sqrt{2}h
    [/tex]
    means: [tex]
    1=h\sqrt{2}
    [/tex] ? and h=0.707 ?
     
    Last edited: Apr 28, 2010
  4. Apr 28, 2010 #3
    Re: differentiation

    Its a typo , the m shouldn't be there . Edited
     
  5. Apr 28, 2010 #4
    Re: differentiation

    thats what confuses me , i am not sure whether thats a typo in the book , i need someone to confirm that for me . What do you think ?
     
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