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!

Directional derivative

  1. Jan 31, 2010 #1
    1. The problem statement, all variables and given/known data

    Find the Directional derivative of [tex]\varphi[/tex] = x2+siny-xz in the direction of i+2j-2k at the point (1, [tex]\pi[/tex]/2 , -3)

    3. The attempt at a solution

    u = i+2j-2k

    [tex]\left|[/tex]u[tex]\left|[/tex] = [tex]\sqrt{1^2+2^2+(-2)^2}[/tex] = 3


    [tex]\Rightarrow[/tex] u[tex]\hat{}[/tex] = 1/3i+2/3j-2/3k

    [tex]\nabla[/tex][tex]\varphi[/tex] = (2x-z)i+(Cos y)j-xk

    at the point (1, [tex]\pi[/tex]/2 , -3)
    u[tex]\hat{}[/tex][tex]\nabla[/tex][tex]\varphi[/tex] = 5/3 + 0 +2/3 = 7/3

    i think i have this right?
     
  2. jcsd
  3. Jan 31, 2010 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    I think you have it right.
     
  4. Jan 31, 2010 #3
    thanks a mill
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Directional derivative
  1. Directional derivatives (Replies: 11)

Loading...