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!

Homework Help: F(x, y, z) = 0 f(x, y, z) =

  1. Jul 3, 2010 #1
    f(x, y, z) = 0 f(x, y, z) = ....

    1. The problem statement, all variables and given/known data

    [PLAIN]http://www.netbookolik.com/wp-content/uploads/2010/07/q12.png [Broken]

    2. Relevant equations

    3. The attempt at a solution

    Sorry have no idea:(
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jul 3, 2010 #2


    User Avatar
    Science Advisor

    Re: f(x, y, z) = 0 f(x, y, z) = ....

    If a surface is given by f(x,y,z)= 0 (or any constant) we can think of it as a "level surface" so [itex]\nabla f= f_x\vec{i}+ f_y\vec{j}+ f_z\vec{k}[/itex] is normal to the surface. The tangent plane at [itex](x_0,y_0,z_0)[/itex] is of the form [itex]f_x(x_0,y_0,z_0)(x- x_0)+[/itex][itex] f_y(x_0,y_0,z_0)(y-y_0)+ f_z(x_0,y_0, z_0)(z- z_0)= 0[/itex].

    For what [itex](x_0, y_0, z_0)[/itex] does (0, 0, 0) lie on that tangent plane?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook