Results 1 to 2 of 2

Math Help - Surface area plz help me

  1. #1
    Newbie
    Joined
    Jan 2009
    Posts
    8

    Surface area plz help me

    Find the surface area of the surface of revolution generated by revolving the graph y=x3, 0x7 around the x-axis.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member
    Joined
    Dec 2008
    Posts
    319
    The formula for the area of a surface of revolution about the x-axis is

    <br />
\begin{array}{rcl}<br />
\mbox{surface area}&=&\int_{x_1}^{x_2}2\pi y\,ds\\<br />
&=&2\pi\int_{x_1}^{x_2}y\sqrt{1+\left(\frac{dy}{dx  }\right)^2}\,dx.<br />
\end{array}<br />

    We get this from the formula for the area of a cone frustum.

    In our case, the integral becomes

    2\pi \int_0^7 x^3\sqrt{1+(3x^2)^2}\,dx.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Surface Area of Surface
    Posted in the Calculus Forum
    Replies: 1
    Last Post: November 1st 2010, 10:53 AM
  2. Calculate the surface area of the surface
    Posted in the Calculus Forum
    Replies: 2
    Last Post: June 26th 2009, 05:03 AM
  3. Lateral Area and Total Surface Area
    Posted in the Geometry Forum
    Replies: 1
    Last Post: May 25th 2009, 05:28 PM
  4. Help finding surface area of a surface
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 3rd 2008, 05:11 PM
  5. Volume, Surface Area, and Lateral Surface Area
    Posted in the Geometry Forum
    Replies: 1
    Last Post: April 15th 2008, 12:40 AM

Search Tags


/mathhelpforum @mathhelpforum