Results 1 to 2 of 2

Math Help - surface area calculation using differntials, Help plz

  1. #1
    Newbie
    Joined
    Nov 2008
    Posts
    2

    surface area calculation using differntials, Help plz

    The surface area of a cone with radius r and height h is given by the formula:a= pi r^2 + pi r sqr(pi ^2 + h^2) . A particular cone has a radius of 3 cm and a height of 8 cm. a) Use differentials to estimate how much the surface area would increase if only the radius was increased by 0.2 cm.b)Use differentials to estimate how much the surface area would increase if only the height was increased by 0.2 cm.

    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member Spec's Avatar
    Joined
    Aug 2007
    Posts
    318
    A=\pi r^2 + \pi r \sqrt{\pi^2 + h^2}

    Then the differential is:

    dA=A'_r dr + A'_h dh

    Determine the partial derivatives, and then use the values for dr and dh that are given (i.e., dr=0.2 [cm] in the first case).
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Calculate the surface area of the surface
    Posted in the Calculus Forum
    Replies: 2
    Last Post: June 26th 2009, 04:03 AM
  2. percentage area calculation
    Posted in the Advanced Applied Math Forum
    Replies: 2
    Last Post: January 15th 2009, 12:45 AM
  3. Help finding surface area of a surface
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 3rd 2008, 04:11 PM
  4. Probability and Area calculation
    Posted in the Statistics Forum
    Replies: 0
    Last Post: July 20th 2008, 04:05 AM
  5. Volume, Surface Area, and Lateral Surface Area
    Posted in the Geometry Forum
    Replies: 1
    Last Post: April 14th 2008, 11:40 PM

Search Tags


/mathhelpforum @mathhelpforum