1. Limited time only! Sign up for a free 30min personal 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!

Surface area of parametric equation

  1. Aug 4, 2009 #1
    1. The problem statement, all variables and given/known data
    For the surface with parametric equations r(st)=<st, s+t, s-t>, find the equation of the tangent plane at (2,3,1).
    Find the surface area under the restriction s^2 + t^2 <=(lessthanorequalto) 1


    2. Relevant equations



    3. The attempt at a solution
    I already figured out the equation of the tangent plane: -2x+3y-z=4, but I am not sure how to find the surface area? I want to use the SA equation |rs x rt| integrated from ds 0 to 1 and dt 0 to 2pi but i am not having much luck. Any ideas?
     
  2. jcsd
  3. Aug 6, 2009 #2
    If you are integrating with dA=ds dt, from ds 0 to 1, then dt would be 0 to [tex]\sqrt{1-s^2}[/tex]. Try converting the double integral to polar coordinates with dA=r dr d_theta.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook