1. Not finding help here? Sign up for a free 30min 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!

Need help deriving an equation

  1. Mar 12, 2005 #1
    I can't figure out how to derive this. This is the formula for the volume of a cone. R is a constant and the side of the cone. Can be any real number.

    If anyone could take a crack at deriving this id be very greatful!

    [tex]V = \pi/3 * (R(1 - x/2\pi))^2 * \sqrt{(R^2 - (R(1 - x/2\pi))^2}[/tex]
     
  2. jcsd
  3. Mar 12, 2005 #2
    Is that your formula or the one you need to derive? And what exactly are you tring to derive? The formula for the volume of a cone?
     
  4. Mar 12, 2005 #3

    dextercioby

    User Avatar
    Science Advisor
    Homework Helper

    [tex]V=\frac{\pi r^{2}h}{3} [/tex]

    .If the (semi)cone is rectangular (the axis joining the top and the center of the base (assumed a circle)),then u can use Pythagora's theorem

    [tex] R^{2}=r^{2}+h^{2} [/tex] and then can express the volume in terms of "R" and either the height "h",or the radius of the circle (the base) "r".

    Daniel.
     
  5. Mar 12, 2005 #4
    r = R(1-x/2pi)
    h = sqrt( R^2 - ( R (1-x/2pi)))

    these are put into the formula for the volume of the cone. Now I need to derive that equation to know which x will give the max volume of the cone.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?