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!

Vector Question

  1. Jun 21, 2009 #1
    1. The problem statement, all variables and given/known data
    A plane has 3x-3z+3 = 0 as it's cartesian equation. Determine the cartesian equation of a plane that is perpendicular to this plane and contains the point P(2,9,-3)

    3. The attempt at a solution
    Since (3,0 ,-3) is the normal for the first plane, I figured it to be a dir'n vector for the second.

    Now to find the cartesian eq'n I'd need to cross two direction vectors but I only have one. So I figure if I find AP, where A is a point on the plane and P is the point on the new plane, then I'd cross the two to find the new "normal" and thus the cartesian equation.

    However, I am unsure of what point to use; should I just plug in random point to plane 1 to find A? How am I certain it is in the same direction as the perpindicular plane... or maybe I'm just approaching the question all wrong.

    Any help would be greatly appreciated as I am getting prepared for my final.

    p.s. if anyone knows how to find the derivative of (tan^3)2x, it'd be greatly appreciated
     
  2. jcsd
  3. Jun 21, 2009 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    If all you have is the point P and a direction vector, then you can make any choice of a second direction vector and the resulting plane will still be perpendicular to the original one. I guess you can pick any one you like. If you mean (tan(2x))^3, I would use the chain rule to differentiate it.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Vector Question
  1. Vector question (Replies: 2)

  2. Vector question (Replies: 3)

  3. Vector question (Replies: 10)

  4. Vector question (Replies: 2)

  5. Vectors question (Replies: 8)

Loading...