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: Another change in unit vectors (d(r-hat)/d(theta)) in Cylindrical

  1. Nov 18, 2011 #1
    1. The problem statement, all variables and given/known data

    Does anyone know what d(r-hat)/d(theta) in Cylindrical coordinates is?

    2. Relevant equations

    3. The attempt at a solution

    I'm pretty sure its -(theta-hat) but I'm not sure, any help?

    Thanks so much
  2. jcsd
  3. Nov 18, 2011 #2
    so theta is moved over by d(theta) shifting over r-hat and theta-hat.. What would d(r-hat)/d(theta) be?
  4. Nov 18, 2011 #3
    anyone? :)
  5. Nov 18, 2011 #4

    I like Serena

    User Avatar
    Homework Helper

    Hi khfrekek1992! :smile:

    [tex]{d\hat r \over d\theta} = \hat \theta[/tex]

    If you draw [itex]\hat r[/itex] for 2 angles, you'll see that the vector-difference between them points in the direction of [itex]\hat \theta[/itex].
    Its (approximate) length is [itex]d\theta[/itex].
  6. Nov 18, 2011 #5
    Oh! I see how you get that now.. Thanks so much! That helps a ton :D
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook