Results 1 to 2 of 2

Math Help - Calculus problem with lengths of curves

  1. #1
    Newbie
    Joined
    Sep 2009
    Posts
    15

    Calculus problem with lengths of curves

    Let L be the length of the curve y = f(x), q </= x </= u, where f is positibe and has a continuous derivative. Let Sf be the surface area generated by rotating the curve about the x-axis. If c is a positive constant, define g(x) = f(x) + c and let Sg be the corresponding surface area generated by the curve y = g(x), q </= x </= u. Express Sg in terms of Sf and L.

    I can't get it. It's a homework problem!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    May 2008
    Posts
    2,295
    Thanks
    7
    Quote Originally Posted by jamessmith View Post
    Let L be the length of the curve y = f(x), q </= x </= u, where f is positibe and has a continuous derivative. Let Sf be the surface area generated by rotating the curve about the x-axis. If c is a positive constant, define g(x) = f(x) + c and let Sg be the corresponding surface area generated by the curve y = g(x), q </= x </= u. Express Sg in terms of Sf and L.

    I can't get it. It's a homework problem!
    S_g=2\pi \int_q^u g(x) \ ds=2\pi \int_q^u f(x) \ ds + 2 \pi \int_q^u c \ ds=S_f + 2\pi c L.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Polar Curves and Arc Lengths
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 11th 2011, 11:14 AM
  2. finding lengths of curves
    Posted in the Calculus Forum
    Replies: 4
    Last Post: November 26th 2010, 07:41 AM
  3. Lengths of Curves
    Posted in the Calculus Forum
    Replies: 4
    Last Post: April 3rd 2010, 06:46 PM
  4. Lengths of Curves
    Posted in the Calculus Forum
    Replies: 2
    Last Post: January 18th 2010, 03:32 AM
  5. Lengths of Plane Curves
    Posted in the Calculus Forum
    Replies: 2
    Last Post: February 24th 2009, 05:59 PM

Search Tags


/mathhelpforum @mathhelpforum