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!

Find the point on the surface

  1. Nov 22, 2009 #1
    1. The problem statement, all variables and given/known data
    Find the point on the surface
    z=exp(sin(x+y)) that is closest to the origin(0,0,0)


    2. Relevant equations



    3. The attempt at a solution
    x = 0, y = 0
    z = exp(sin(0)) = exp(0) = 1
    The point on the surface z=exp(sin(x+y)) that is closest to the origin (0,0,0) is (0,0,1)
     
  2. jcsd
  3. Nov 22, 2009 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi tuablink! Welcome to PF! :smile:
    Nooo :redface:

    let the distance squared = r2 = x2 + y2 + z2.

    Is ∂(r2)/∂x = 0 at (0,0,1) ? :wink:
     
  4. Nov 22, 2009 #3

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Why have you started a new thread?? :confused:
    Noooo! :redface:

    Two equations … solve('2*x + 2*exp(2*sin(x + y))*cos(x + y) = 2*y + 2*exp(2*sin(x + y))*cos(x + y) = 0') :wink:
     
  5. Nov 22, 2009 #4
    Could you give me hints or guide me?
    thank you
     
  6. Nov 22, 2009 #5

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    uhh?

    ok …

    solve('

    2*x + 2*exp(2*sin(x + y))*cos(x + y) =

    2*y + 2*exp(2*sin(x + y))*cos(x + y) =

    0') :wink:
     
  7. Nov 22, 2009 #6
    I tried and it gave me an error "Warning: Explicit solution could not be found"
     
  8. Nov 22, 2009 #7

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    oh put the computer down and just look at the two equations. :rolleyes:
     
  9. Nov 22, 2009 #8

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    Re: How can I find the point on the surface?

    How did you decide x=0, y=0? However you did it, it's not right. What's an expression for the distance from (x,y,z) to the origin?
     
    Last edited by a moderator: Nov 22, 2009
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook